Measure keyboard continuation and navigation feedback

Assistant: codex
Assistant-Model: gpt-6-astra
Assistant-Session: 01a0cffe-206f-7323-89d3-b20ca4cf4bf9

TREE.md

@@ -351,6 +351,8 @@ research/evolution/EvolutionReport.md
 research/evolution/README.md
 research/evolution/context.json
 research/evolution/cycles/2026-09-27-navigation-effort.json
+research/evolution/cycles/2026-09-27-navigation-focus-effort.json
+research/evolution/cycles/2026-09-27-navigation-focus.md
 research/evolution/cycles/2026-09-27-navigation.md
 research/evolution/ledger.json
 research/evolution/profiles.json
@@ -400,6 +402,9 @@ research/experiments/matrix-recovery/provenance.json
 research/experiments/matrix-recovery/result.json
 research/experiments/navigation-history/README.md
 research/experiments/navigation-history/experiment.mjs
+research/experiments/navigation-history/focus-policy.js
+research/experiments/navigation-history/focus-result.json
+research/experiments/navigation-history/focus.mjs
 research/experiments/navigation-history/initial-partial.json
 research/experiments/navigation-history/package-lock.json
 research/experiments/navigation-history/package.json
@@ -423,6 +428,7 @@ research/reviews/LocalFirstAdmissionScreen.json
 research/reviews/LocalFirstEvidenceExpansion.md
 research/reviews/MatrixRecoveryExperiment.md
 research/reviews/NavigationCoverage.md
+research/reviews/NavigationFocusExperiment.md
 research/reviews/NavigationHistoryExperiment.md
 research/reviews/NavigationRenderingEvidence.md
 research/reviews/NestedDismissalIsolation.md

research/candidates/FocusReturn.md

@@ -74,3 +74,14 @@ requires application policy. This supports separating input ownership from focus
 restoration, not a general production-ready fix: animated exits, competing owners,
 rapid input bursts and assistive technology remain untested. Sixteen hypotheses;
 no new pattern or maturity promotion.
+
+## Boundary with route continuation — 2026-09-27
+
+[Navigation focus contrast](../reviews/NavigationFocusExperiment.md) NF02–NF06
+provides a non-modal counter-context: a successful route may continue at a new heading,
+while failed navigation keeps the invoker and background work leaves focus alone.
+A held response must respect focus moved to a surviving search field. Raw htmx in
+this fixture restores a same-ID link; that behavior alone does not choose the next
+task. Preserve this candidate's modal scope instead of treating every route change
+as a return-to-invoker problem. No general route-focus pattern or AT validation is
+admitted; delayed history restoration and competing navigation remain open.

research/candidates/ProgressiveEnhancement.md

@@ -50,3 +50,18 @@ native recovery link navigates successfully. This does not establish automatic f
 late-script safety, accessible focus/announcements or offline availability.
 See [NH01–NH06](../reviews/NavigationHistoryExperiment.md). One authored application
 with a real package, not independent deployed recurrence. Hypothesis retained.
+
+## Keyboard continuation and feedback — 2026-09-27
+
+[Navigation focus experiment](../reviews/NavigationFocusExperiment.md) NF01–NF06
+distinguishes successful route continuation, failed navigation, history restoration
+and background updates. In the raw fixture, a replacement link retains focus but
+fragment navigation leaves the old title and failures produce no visible status.
+The authored policy updates title/status, selects a heading for direct continuation
+and preserves a surviving control when the user has moved focus during the request.
+
+Choose a continuation policy for the task; do not universally focus a heading or
+return to the invoker. Check ownership when the response is applied, not only when
+it is requested. Failure feedback need not move focus. Same-ID restoration is not
+proof of semantic continuity. DOM/ARIA checks here do not establish spoken feedback;
+AT, delayed history and overlapping-request behavior remain unverified.

research/catalog/SourceCatalog.md

@@ -173,3 +173,19 @@ binaries. Authored HTTP application; 18 browser cases plus explicit HTTP validat
 sequence repeated twice. [NH01–NH06 review](../reviews/NavigationHistoryExperiment.md),
 preregistered prospective corroboration. This is one implementation family, not
 an independent production deployment. Initial launch failure receipt preserved.
+
+## Navigation focus and feedback — 2026-09-27
+
+SRC-0038 follow-up: [NF01–NF06](../reviews/NavigationFocusExperiment.md), separate
+focus runner and authored policy using the same pinned htmx fixture family. 22
+registered keyboard/DOM rows; not assistive-technology validation or independent use.
+
+SRC-0039: [W3C Understanding Focus Order](https://www.w3.org/WAI/WCAG22/Understanding/focus-order.html)
+and [Status Messages](https://www.w3.org/WAI/WCAG22/Understanding/status-messages.html),
+primary interpretive guidance accessed 2026-09-27; living revision unknown. One W3C
+family, not two application uses. NF review limits the inference to meaningful focus
+order and programmatically exposed feedback; no conformance claim from this fixture.
+
+SRC-0040: [htmx events](https://htmx.org/events/), lifecycle-hook reference accessed
+2026-09-27, living revision unknown. Same htmx family as SRC-0018/0019 and SRC-0038.
+Runtime conclusions use pinned 2.0.11 code and hashed receipts.

research/evolution/EvolutionReport.md

@@ -22,7 +22,7 @@ Independent human profile reviews: 0/17. Full-contract independent-use counts un
 
 ## Change since baseline
 
-Baseline baseline-2026-09-26; source revision `f273a190f0e08b8cfe0bb7260d0e7d889f1c090a`. Added: 0; removed: 0; shared candidates with changed content: 2; changed evidence/review assessments: 2; maturity transitions: 0.
+Baseline baseline-2026-09-26; source revision `f273a190f0e08b8cfe0bb7260d0e7d889f1c090a`. Added: 0; removed: 0; shared candidates with changed content: 3; changed evidence/review assessments: 3; maturity transitions: 0.
 
 The shared cohort is compared separately from additions. Changed text or evidence counts are not learning gains.
 
@@ -51,13 +51,13 @@ Ten selected retrospective outcomes (not a historical census), followed by prosp
 
 | Outcome | Entries (not independent discoveries) |
 | --- | ---: |
-| corroboration | 1 |
+| corroboration | 2 |
 | inconclusive | 0 |
 | merge | 0 |
 | rejection | 0 |
 | revision | 10 |
 
-Cycles with recorded research effort: 1/11. Unknown effort is neither zero nor estimated from commits, tokens or assertion counts.
+Cycles with recorded research effort: 2/12. Unknown effort is neither zero nor estimated from commits, tokens or assertion counts.
 
 ### Stream B / B-navigation-mechanism-v1
 
@@ -67,11 +67,19 @@ Cycles with recorded research effort: 1/11. Unknown effort is neither zero nor e
 
 One bounded question counts at most one consequential outcome. Corroboration and inconclusive work remain visible separately. Fewer than three comparable cycles: no trend assessment.
 
+### Stream F / F-navigation-focus-v1
+
+| Cycle | Outcome | Research minutes | Consequential outcome/hour |
+| --- | --- | ---: | ---: |
+| LEARN-0012 | corroboration | 5.138 | 0.00 |
+
+One bounded question counts at most one consequential outcome. Corroboration and inconclusive work remain visible separately. Fewer than three comparable cycles: no trend assessment.
+
 ## Coherence and maintainability
 
 Profile hashes and local references passed validation when this report was generated. That checks traceability, not source truth or external URL freshness.
 
-Profiles with unknown last substantive review date: 15. Assessment dates record this metadata review, not a new substantive validation. No age-based freshness claim is available for those profiles.
+Profiles with unknown last substantive review date: 14. Assessment dates record this metadata review, not a new substantive validation. No age-based freshness claim is available for those profiles.
 
 Coherence metrics (ambiguous selections, unjustified relations and overlap resolved): not measured. Conflict Copy / Explicit Reconciliation overlap remains an explicit open question.
 
@@ -230,8 +238,9 @@ Keep essential actions usable when enhancement is unavailable.
 | documentary | htmx | Boosted links and forms. | [NavigationRenderingEvidence](../../research/reviews/NavigationRenderingEvidence.md) |
 | documentary | SvelteKit | Form actions and rendering/page options. | [NavigationRenderingEvidence](../../research/reviews/NavigationRenderingEvidence.md) |
 | runtime | htmx in authored public-catalog fixture | NH01–NH06: native/enhanced routes, history hit/miss, actual browser cache ordering and missing-Vary negative control; explicit Node validator checks separate. | [NavigationHistoryExperiment](../../research/reviews/NavigationHistoryExperiment.md) |
+| runtime | htmx in authored public-catalog fixture | NF01–NF06: Tab/Enter navigation, raw versus authored focus/status policy, held-response ownership and background update; DOM evidence only, not AT speech. | [NavigationFocusExperiment](../../research/reviews/NavigationFocusExperiment.md) |
 
-Open limits: Independent deployed full-contract recurrence remains unverified. Keyboard/focus/announcements, late-script activation, interrupted transport, invalid/deleted routes, offline availability and real intermediary behavior remain open.
+Open limits: Independent deployed full-contract recurrence and human/AT validation remain unverified. Focus visibility, delayed history, overlapping requests, late-script activation, interrupted transport, invalid/deleted routes, offline availability and real intermediaries remain open.
 
 Superseded by: none recorded.
 
@@ -318,8 +327,9 @@ Restore meaningful focus after a temporary interaction ends.
 | documentary | WAI-ARIA APG | Dialog focus obligations. | [PatternBreadthExpansion](../../research/reviews/PatternBreadthExpansion.md) |
 | static-code | Radix | Pinned layer/listener ownership implementation. | [NestedDismissalIsolation](../../research/reviews/NestedDismissalIsolation.md) |
 | runtime | Radix | Authored fixture: raw 20/24 versus routed 24/24; browser/build limits retained. | [NestedOwnershipRouting](../../research/reviews/NestedOwnershipRouting.md) |
+| runtime | htmx in authored public-catalog fixture | NF01–NF06: Tab/Enter navigation, raw versus authored focus/status policy, held-response ownership and background update; DOM evidence only, not AT speech. | [NavigationFocusExperiment](../../research/reviews/NavigationFocusExperiment.md) |
 
-Open limits: One implementation family; repeated trials are not independent uses. Animated exits and competing owners remain untested; no production repair claim.
+Open limits: One implementation family; repeated trials are not independent uses. Animated exits and competing owners remain untested; no production repair claim. Route continuation is a contrasting context, not independent modal-pattern recurrence; delayed history and AT speech unverified.
 
 Superseded by: none recorded.
 
@@ -495,3 +505,17 @@ Evidence: [NavigationHistoryExperiment](../../research/reviews/NavigationHistory
 Remaining uncertainty: One authored application, no independent recurrence or usefulness gain. Accessibility, delayed scripts, interrupted transport, real intermediaries and offline availability remain open.
 
 Supersedes: none recorded.
+
+### LEARN-0012 — Does enhanced route replacement need explicit continuation and feedback policy that respects changed focus ownership?
+
+2026-09-27 · stream F · prospective · corroboration
+
+Before: Native controls alone do not establish enhanced focus/feedback semantics; delayed responses should respect focus moved to another surviving task. Modal return is not automatically route continuation.
+
+Conclusion: Corroborated in 22 cases: raw same-ID link focus survives but this fragment contract leaves stale title and silent failure; authored heading/status policy works and preserves newer search focus. No AT speech or universal heading policy established.
+
+Evidence: [NavigationFocusExperiment](../../research/reviews/NavigationFocusExperiment.md), [focus-result](../../research/experiments/navigation-history/focus-result.json), [2026-09-27-navigation-focus-effort](../../research/evolution/cycles/2026-09-27-navigation-focus-effort.json).
+
+Remaining uncertainty: Author-model DOM evidence, no human/AT validation or independent recurrence. Delayed history focus, competing requests, delayed scripts and interrupted enhancement remain open.
+
+Supersedes: none recorded.

research/evolution/cycles/2026-09-27-navigation-focus-effort.json

@@ -0,0 +1,34 @@
+{
+  "start": 198900.113504947,
+  "execution_seconds": 31.501304913981585,
+  "executions": [
+    {
+      "command": [
+        "node",
+        "research/experiments/navigation-history/focus.mjs"
+      ],
+      "seconds": 17.86536105797859,
+      "exit_code": 0
+    },
+    {
+      "command": [
+        "make",
+        "evolution-check",
+        "evolution-test",
+        "schema-test",
+        "bench-test"
+      ],
+      "seconds": 13.635943856002996,
+      "exit_code": 0
+    }
+  ],
+  "status": "complete",
+  "start_utc_approx": "2026-09-26T22:16:12.694172+00:00",
+  "end_utc": "2026-09-26T22:21:52.471986+00:00",
+  "elapsed_seconds": 339.778,
+  "research_minutes": 5.138,
+  "execution_minutes": 0.525,
+  "method": "Single-agent monotonic elapsed session minus blocking experiment/check subprocess durations. Checkpoint inspection assigned to execution; no double count. Rounded minute fields are elapsed agent effort, not human labor or model compute.",
+  "excluded": "Orientation before clock; final receipt refresh, commit, snapshot and State Hub sync after cutoff. Tokens and cost unknown.",
+  "budget": "Within preregistered 45 active research / 10 execution minute budget."
+}

research/evolution/ledger.json

@@ -373,6 +373,43 @@
         "cost_usd": null
       },
       "supersedes": []
+    },
+    {
+      "id": "LEARN-0012",
+      "date": "2026-09-27",
+      "recording": "prospective",
+      "stream": "F",
+      "comparison_group": "F-navigation-focus-v1",
+      "protocol_ref": "research/evolution/cycles/2026-09-27-navigation-focus.md",
+      "question": "Does enhanced route replacement need explicit continuation and feedback policy that respects changed focus ownership?",
+      "previous_belief": "Native controls alone do not establish enhanced focus/feedback semantics; delayed responses should respect focus moved to another surviving task. Modal return is not automatically route continuation.",
+      "conclusion": "Corroborated in 22 cases: raw same-ID link focus survives but this fragment contract leaves stale title and silent failure; authored heading/status policy works and preserves newer search focus. No AT speech or universal heading policy established.",
+      "disposition": "corroboration",
+      "affected_patterns": [
+        "CAND-0010",
+        "CAND-0016"
+      ],
+      "evidence": [
+        "research/reviews/NavigationFocusExperiment.md",
+        "research/experiments/navigation-history/focus-result.json",
+        "research/evolution/cycles/2026-09-27-navigation-focus-effort.json"
+      ],
+      "remaining_uncertainty": [
+        "Author-model DOM evidence, no human/AT validation or independent recurrence.",
+        "Delayed history focus, competing requests, delayed scripts and interrupted enhancement remain open."
+      ],
+      "reviewer": {
+        "name": "Codex",
+        "role": "author-model",
+        "independent_human": false
+      },
+      "effort": {
+        "research_minutes": 5.138,
+        "execution_minutes": 0.525,
+        "reported_tokens": null,
+        "cost_usd": null
+      },
+      "supersedes": []
     }
   ]
 }

research/evolution/profiles.json

@@ -359,7 +359,7 @@
       "id": "CAND-0010",
       "path": "research/candidates/ProgressiveEnhancement.md",
       "title": "Progressive Enhancement",
-      "sha256": "e9ca2b046cb69fff16379e22e1a9d0d61d2a5801ff92bbfc1b56ae3e3be16c7c",
+      "sha256": "ec3ab16d680308593af4d22fbbcbea737fe46096c5f3e65968d0db3a8befec21",
       "status": "draft",
       "maturity": "hypothesis",
       "decision": "Keep essential actions usable when enhancement is unavailable.",
@@ -381,6 +381,12 @@
           "family": "htmx in authored public-catalog fixture",
           "ref": "research/reviews/NavigationHistoryExperiment.md",
           "scope": "NH01–NH06: native/enhanced routes, history hit/miss, actual browser cache ordering and missing-Vary negative control; explicit Node validator checks separate."
+        },
+        {
+          "kind": "runtime",
+          "family": "htmx in authored public-catalog fixture",
+          "ref": "research/reviews/NavigationFocusExperiment.md",
+          "scope": "NF01–NF06: Tab/Enter navigation, raw versus authored focus/status policy, held-response ownership and background update; DOM evidence only, not AT speech."
         }
       ],
       "independent_full_contract_uses": null,
@@ -392,8 +398,8 @@
         "last_substantive_review_date": "2026-09-27"
       },
       "gaps": [
-        "Independent deployed full-contract recurrence remains unverified.",
+        "Independent deployed full-contract recurrence and human/AT validation remain unverified.",
-        "Keyboard/focus/announcements, late-script activation, interrupted transport, invalid/deleted routes, offline availability and real intermediary behavior remain open."
+        "Focus visibility, delayed history, overlapping requests, late-script activation, interrupted transport, invalid/deleted routes, offline availability and real intermediaries remain open."
       ],
       "superseded_by": []
     },
@@ -560,7 +566,7 @@
       "id": "CAND-0016",
       "path": "research/candidates/FocusReturn.md",
       "title": "Focus Return",
-      "sha256": "b44f976684d7f2a9186e09aaa6fd6fdb51dc5674a53bcc90afa08748a641f041",
+      "sha256": "129ef7623d11da91f3f5429686455be16180e5477d1706836f5c1c3617698eae",
       "status": "draft",
       "maturity": "hypothesis",
       "decision": "Restore meaningful focus after a temporary interaction ends.",
@@ -582,19 +588,26 @@
           "family": "Radix",
           "ref": "research/reviews/NestedOwnershipRouting.md",
           "scope": "Authored fixture: raw 20/24 versus routed 24/24; browser/build limits retained."
+        },
+        {
+          "kind": "runtime",
+          "family": "htmx in authored public-catalog fixture",
+          "ref": "research/reviews/NavigationFocusExperiment.md",
+          "scope": "NF01–NF06: Tab/Enter navigation, raw versus authored focus/status policy, held-response ownership and background update; DOM evidence only, not AT speech."
         }
       ],
       "independent_full_contract_uses": null,
       "review": {
-        "assessed_at": "2026-09-26",
+        "assessed_at": "2026-09-27",
         "reviewer": "Codex",
         "role": "author-model",
         "independent_human": false,
-        "last_substantive_review_date": null
+        "last_substantive_review_date": "2026-09-27"
       },
       "gaps": [
         "One implementation family; repeated trials are not independent uses.",
-        "Animated exits and competing owners remain untested; no production repair claim."
+        "Animated exits and competing owners remain untested; no production repair claim.",
+        "Route continuation is a contrasting context, not independent modal-pattern recurrence; delayed history and AT speech unverified."
       ],
       "superseded_by": []
     },

research/experiments/navigation-history/README.md

@@ -38,3 +38,18 @@ History eviction uses htmx 2.0.11's sessionStorage key, an experimental control
 to the pinned implementation. No assertion of identical content freshness across
 history, general offline availability, accessibility, script-late races, writes,
 real intermediary correctness or independent full-pattern recurrence follows.
+
+## Keyboard/focus follow-up
+
+[Preregistered LEARN-0012](../../evolution/cycles/2026-09-27-navigation-focus.md),
+[review](../../reviews/NavigationFocusExperiment.md), [receipt](focus-result.json).
+Run the same browser environment with `node focus.mjs`. Output defaults to
+`/tmp/fep-focus-result.json`; choose a fresh `FEP_RESULT_PATH` per execution.
+The separate focus runner/policy preserve the earlier navigation/cache inputs and
+receipt hashes. Same locked packages. 22 cases: native keyboard plus raw/managed
+navigation, 503 feedback, held-response focus ownership, history and background work.
+
+Raw rows observe behavior, so 22 passing rows do not mean raw and managed variants
+meet identical focus/feedback obligations. See NF01–NF06. The policy is authored
+experimental code; DOM focus and live-region text do not establish assistive-technology
+announcements or conformance. History and request-race limits remain explicit.

research/experiments/navigation-history/focus-policy.js

@@ -0,0 +1,32 @@
+// Authored experimental navigation policy; raw variant installs only diagnostics.
+window.probe=[];
+const managed=new URL(location.href).searchParams.get('mode')==='managed';
+const pending=new WeakMap();
+const notice=message=>{document.querySelector('#feedback').textContent=message;};
+function complete(moveFocus){
+ const heading=document.querySelector('#heading');
+ document.title=`${heading.textContent} — Catalog`;
+ notice(`Loaded ${heading.textContent}`);
+ if(moveFocus)heading.focus();
+}
+document.addEventListener('htmx:beforeRequest',e=>{
+ if(managed&&e.detail.target.id==='content')pending.set(e.detail.xhr,{source:e.detail.elt,ownsFocus:false});
+});
+document.addEventListener('htmx:beforeSwap',e=>{
+ const state=pending.get(e.detail.xhr);
+ if(state)state.ownsFocus=document.activeElement===state.source;
+});
+document.addEventListener('htmx:afterSwap',e=>{
+ const state=pending.get(e.detail.xhr);
+ if(state){complete(state.ownsFocus);pending.delete(e.detail.xhr);}
+});
+document.addEventListener('htmx:responseError',e=>{
+ if(managed&&pending.has(e.detail.xhr)){
+  notice('Navigation failed. Current article retained. Use Native recovery to continue.');
+  pending.delete(e.detail.xhr);
+ }
+});
+document.addEventListener('htmx:historyRestore',()=>{if(managed)complete(true);});
+for(const name of ['htmx:afterSettle','htmx:historyRestore','htmx:responseError']){
+ document.addEventListener(name,()=>window.probe.push({name,focus:document.activeElement.id||document.activeElement.tagName,title:document.title,url:location.href,feedback:document.querySelector('#feedback').textContent}));
+}

research/experiments/navigation-history/focus.mjs

@@ -0,0 +1,74 @@
+import {chromium,firefox} from 'playwright';
+import {createServer} from 'node:http';
+import {once} from 'node:events';
+import {readFile,writeFile} from 'node:fs/promises';
+import {createHash} from 'node:crypto';
+import assert from 'node:assert/strict';
+const dir=new URL('.',import.meta.url);
+const htmx=await readFile(new URL('node_modules/htmx.org/dist/htmx.js',dir));
+const policy=await readFile(new URL('focus-policy.js',dir));
+let requests=[],release=null,heldResolve=null;
+const server=createServer((req,res)=>{
+ const u=new URL(req.url,'http://local');res.setHeader('Cache-Control','no-store');
+ const hx=req.headers['hx-request']==='true';requests.push({path:req.url,hx,restore:req.headers['hx-history-restore-request']==='true'});
+ if(u.pathname==='/htmx.js'||u.pathname==='/policy.js'){res.setHeader('Content-Type','application/javascript');res.end(u.pathname==='/htmx.js'?htmx:policy);return;}
+ if(u.pathname==='/news'){res.end('<p>Background news updated</p>');return;}
+ if(u.pathname!=='/articles'){res.writeHead(404);res.end('Not found');return;}
+ const topic=u.searchParams.get('topic')==='beta'?'beta':'alpha',mode=u.searchParams.get('mode')==='managed'?'managed':'raw';
+ const target=`/articles?topic=${topic==='alpha'?'beta':'alpha'}&mode=${mode}`;
+ const boost='hx-boost="true" hx-target="#content" hx-select="#content" hx-swap="outerHTML"';
+ const content=`<main id="content" hx-history-elt><h1 id="heading" tabindex="-1">${topic}</h1><p>Article ${topic}</p><a id="next" href="${target}" ${boost}>Other topic</a><a id="broken" href="${target}&fail=1" ${boost}>Fail enhanced navigation</a><a id="recover" href="${target}&fail=1">Native recovery</a><a id="slow" href="${target}&slow=1" ${boost}>Delayed navigation</a></main>`;
+ const body=hx?content:`<!doctype html><html lang="en"><head><meta charset="utf-8"><title>${topic} — Catalog</title><meta name="htmx-config" content='{"historyRestoreAsHxRequest":false}'><script src="/policy.js" defer></script><script src="/htmx.js" defer></script></head><body>${content}<label>Persistent search <input id="search"></label><p id="feedback" role="status" aria-live="polite" aria-atomic="true"></p><aside id="news">Initial news</aside></body></html>`;
+ const send=()=>{res.writeHead(hx&&u.searchParams.has('fail')?503:200,{'Content-Type':'text/html'});res.end(hx&&u.searchParams.has('fail')?'Outage':body);};
+ if(hx&&u.searchParams.has('slow')){release=send;heldResolve?.();}else send();
+});
+server.listen(0,'127.0.0.1');await once(server,'listening');const base=`http://127.0.0.1:${server.address().port}`;
+const results=[],browsers={};const output=process.env.FEP_RESULT_PATH||'/tmp/fep-focus-result.json';
+async function inspect(p){return p.evaluate(()=>({focus:document.activeElement.id||document.activeElement.tagName,title:document.title,url:location.href,heading:document.querySelector('h1')?.textContent,feedback:document.querySelector('#feedback')?.textContent,statusRole:document.querySelector('#feedback')?.getAttribute('role'),live:document.querySelector('#feedback')?.getAttribute('aria-live')}));}
+async function tabTo(p,id){for(let i=0;i<12;i++){if((await inspect(p)).focus===id)return;await p.keyboard.press('Tab');}throw Error(`Tab failed to reach ${id}`);}
+async function selected(p,topic){await p.waitForFunction(t=>document.querySelector('h1')?.textContent===t,topic);assert.equal(new URL(p.url()).searchParams.get('topic'),topic);}
+async function settled(p){await p.waitForFunction(()=>window.probe.some(e=>e.name==='htmx:afterSettle'));}
+try{
+ for(const [engine,launcher]of [['chromium',chromium],['firefox',firefox]]){
+  const path=engine==='chromium'?process.env.FEP_CHROMIUM_PATH:undefined;
+  const browser=await launcher.launch({headless:true,...(path?{executablePath:path}:{})});
+  browsers[engine]={version:browser.version(),executable:path||launcher.executablePath(),sha256:createHash('sha256').update(await readFile(path||launcher.executablePath())).digest('hex')};
+  try{
+   async function scenario(id,mode,fn){
+    requests=[];release=null;const context=await browser.newContext({javaScriptEnabled:mode!=='native'});const p=await context.newPage();p.setDefaultTimeout(4000);
+    const r={id,engine,mode,status:'pass'};
+    try{await p.goto(base+`/articles?topic=alpha&mode=${mode}`);if(mode!=='native')await p.waitForFunction(()=>window.htmx?.version==='2.0.11');r.observation=await fn(p);}
+    catch(e){r.status='fail';r.error=e.message;}
+    r.final=await inspect(p).catch(()=>null);r.events=await p.evaluate(()=>window.probe||[]).catch(()=>[]);r.requests=[...requests];results.push(r);
+    if(release){release();release=null;}heldResolve=null;await context.close();await writeFile(output,JSON.stringify({status:'incomplete',results},null,2)+'\n');
+   }
+   await scenario('K01-native-keyboard','native',async p=>{await tabTo(p,'next');await p.keyboard.press('Enter');await selected(p,'beta');assert.equal(await p.title(),'beta — Catalog');return {keyboardLink:true};});
+   for(const mode of ['raw','managed']){
+    await scenario('K02-enhanced-keyboard',mode,async p=>{
+     await tabTo(p,'next');await p.keyboard.press('Enter');await selected(p,'beta');await settled(p);const o=await inspect(p);
+     o.headingContinuation=o.focus==='heading';o.updatedTitle=o.title==='beta — Catalog';o.completionFeedback=o.feedback==='Loaded beta';
+     if(mode==='managed')assert(o.headingContinuation&&o.updatedTitle&&o.completionFeedback);return o;
+    });
+    await scenario('K03-error-feedback-recovery',mode,async p=>{
+     await tabTo(p,'broken');await p.keyboard.press('Enter');await p.waitForFunction(()=>window.probe.some(e=>e.name==='htmx:responseError'));await selected(p,'alpha');const o=await inspect(p);assert.equal(o.focus,'broken');
+     o.failureFeedback=o.feedback.includes('Navigation failed');if(mode==='managed'){assert(o.failureFeedback);assert.equal(o.statusRole,'status');assert.equal(o.live,'polite');}
+     await tabTo(p,'recover');await p.keyboard.press('Enter');await selected(p,'beta');o.nativeRecovery=true;return o;
+    });
+    await scenario('K04-delayed-new-focus',mode,async p=>{
+     const held=new Promise(resolve=>{heldResolve=resolve;});await tabTo(p,'slow');await p.keyboard.press('Enter');await held;await tabTo(p,'search');
+     release();release=null;await selected(p,'beta');await settled(p);const o=await inspect(p);assert.equal(o.focus,'search');if(mode==='managed')assert.equal(o.feedback,'Loaded beta');return o;
+    });
+    await scenario('K05-history-continuation',mode,async p=>{
+     await tabTo(p,'next');await p.keyboard.press('Enter');await selected(p,'beta');await settled(p);await p.goBack();await selected(p,'alpha');await p.waitForFunction(()=>window.probe.some(e=>e.name==='htmx:historyRestore'));
+     const o=await inspect(p);if(mode==='managed'){assert.equal(o.focus,'heading');assert.equal(o.title,'alpha — Catalog');assert.equal(o.feedback,'Loaded alpha');}return o;
+    });
+    await scenario('K06-background-no-theft',mode,async p=>{
+     await tabTo(p,'search');await p.evaluate(()=>htmx.ajax('GET','/news',{target:'#news',swap:'innerHTML'}));await p.locator('#news').filter({hasText:'Background news updated'}).waitFor();
+     const o=await inspect(p);assert.equal(o.focus,'search');assert.equal(o.feedback,'');assert.equal(o.title,'alpha — Catalog');return o;
+    });
+   }
+  }finally{await browser.close();}
+ }
+}finally{if(release)release();await new Promise(resolve=>server.close(resolve));}
+const files={};for(const f of ['focus.mjs','focus-policy.js','package.json','package-lock.json','node_modules/htmx.org/dist/htmx.js'])files[f]=createHash('sha256').update(await readFile(new URL(f,dir))).digest('hex');
+const r={date:new Date().toISOString(),node:process.version,kind:'keyboard-focus-dom-observation-not-assistive-technology-validation',files,browsers,results,passed:results.filter(x=>x.status==='pass').length,total:results.length};await writeFile(output,JSON.stringify(r,null,2)+'\n');console.log(JSON.stringify({output,passed:r.passed,total:r.total,failures:results.filter(x=>x.status==='fail')},null,2));if(r.passed!==r.total)process.exitCode=1;

research/reviews/NavigationCoverage.md

@@ -33,3 +33,10 @@ corroboration to VC-03, URL-addressable State and Progressive Enhancement. Direc
 native/enhanced/history and representation-cache subset exercised in two browsers;
 missing-Vary negative control reproduced. VC-03 stays provisional and offline/
 accessibility work remains open. No maturity or M1/M2 promotion.
+
+## Keyboard continuation evidence — 2026-09-27
+
+[NF01–NF06](NavigationFocusExperiment.md) adds 22 native/raw/managed observations to
+the provisional VC-03 subset. Explicit focus/title/status policy and delayed-response
+ownership exercised; AT speech and full accessibility validation remain pending.
+This is a new stream-F comparison group, not another comparable cache cycle.

research/reviews/NavigationFocusExperiment.md

@@ -0,0 +1,85 @@
+# Keyboard continuation and navigation feedback — 2026-09-27
+
+LEARN-0012; Codex author-model review. [Preregistered protocol](../evolution/cycles/2026-09-27-navigation-focus.md)
+committed as `2b1c9a4` before implementation/execution. New stream-F comparison group
+F-navigation-focus-v1, not comparable to the preceding HTTP/cache question's group.
+[Runner](../experiments/navigation-history/focus.mjs),
+[authored policy](../experiments/navigation-history/focus-policy.js),
+[receipt](../experiments/navigation-history/focus-result.json).
+
+## Evidence and result
+
+Pinned htmx 2.0.11, Playwright 1.63.0; same binary versions/hashes as the previous
+navigation cycle: Chromium 151.0.7922.34 and Firefox 155.0. One run, no harness
+corrections or discarded failures. 22/22 registered rows completed: two native cases,
+ten raw observation cases, ten managed-policy cases. A passing raw observation row
+means it was recorded successfully, not that it satisfies the managed obligations.
+All browser actions initiating navigation use Tab/Enter; background update is
+explicitly script-triggered and browser history uses Playwright's history command.
+
+| Claim | Cases | Observations in both browsers |
+| --- | --- | --- |
+| NF01 | K01 | With scripts disabled, Tab reaches the native link and Enter loads beta with its full-document title |
+| NF02 | K02 | Raw htmx retains focus on the new same-ID `next` link, but this fragment response leaves alpha's title over beta content and produces no completion status. Managed policy focuses beta's heading, updates title and writes `Loaded beta` |
+| NF03 | K03 | Enhanced 503 preserves alpha URL/content and the invoking link's focus in both variants. Only managed policy writes the failure/recovery message; native recovery works by keyboard in both |
+| NF04 | K04 | While a response is held at the server, the user tabs to persistent search. Both variants preserve search focus on release; managed policy reports completion without moving focus |
+| NF05 | K05 | History restores alpha. Raw focus is the same-ID link; managed focus is the heading with matching title/status |
+| NF06 | K06 | An unrelated background region update preserves search focus and does not emit navigation feedback in either variant |
+
+The raw result narrows our anticipation of focus loss: stable IDs let htmx restore
+focus to a replacement element. Here that link now leads back to the other article.
+DOM identity retention alone is not proof of an appropriate next task, but neither is
+this observation proof that retaining the link is always wrong. The server deliberately
+returns a fragment without title metadata; this is an application contract gap, not
+a claim that htmx cannot update document titles.
+
+## Mechanism and interpretation
+
+The authored policy remembers the request source, checks focus ownership immediately
+before a zero-delay swap, and applies the continuation synchronously on afterSwap,
+after the library's own focus restoration. It updates heading/title/status only for
+registered content navigation. It leaves a surviving search control alone if focus
+has moved there. Errors keep focus on the invoker and provide a visible polite status
+message with a native recovery action already present. History uses a separate explicit
+heading policy. It is a small experiment, not a production navigation library.
+
+[W3C focus-order guidance](https://www.w3.org/WAI/WCAG22/Understanding/focus-order.html)
+allows more than one meaningful focus order and does not prescribe one universal target.
+[Status-message guidance](https://www.w3.org/WAI/WCAG22/Understanding/status-messages.html)
+informs making feedback programmatically available without requiring focus movement.
+[htmx events](https://htmx.org/events/) supplies the lifecycle hooks. Living primary
+pages accessed 2026-09-27; exact documentation revisions unknown. Package implementation
+is pinned and hashed. DOM status/ARIA observations are not evidence that a screen reader
+spoke the message; no assistive technology or human evaluation was run.
+
+## Disposition and limits
+
+**Corroboration**, one bounded outcome. Existing Progressive Enhancement already calls
+for focus, feedback and recovery semantics; Focus Return explicitly excludes automatic
+generalization from modal closure to route transitions. The experiment makes that
+boundary concrete and adds an ownership-sensitive candidate mechanism. No newly
+invented pattern, canonical promotion, independent recurrence or usefulness gain.
+
+Add scoped implementation guidance: distinguish successful route continuation, failed
+navigation, history and background updates. Test whether a late response still owns
+focus before moving it. Returning to a modal invoker and continuing into a new page
+are different decisions. Keep both candidates as hypotheses.
+
+Unverified: screen-reader speech (including possible heading/status duplication),
+focus visibility, complete names/order audit, actual usability, pointer modality,
+nonzero swap delays, overlapping/superseded route requests, delayed history responses
+while the user moves focus, script-late activation, interrupted transport and offline
+availability. The explicit history policy always focuses a heading in the tested
+immediate restore; it is not proven safe for an asynchronous history miss. Public
+single-response success does not settle these ownership races. No writes or production
+application were exercised.
+
+[Effort receipt](../evolution/cycles/2026-09-27-navigation-focus-effort.json) separates
+monotonic active agent time from experiment/check subprocess time; final administrative
+refresh/commit/snapshot/sync overhead excluded. No token/cost estimate. One cycle in
+this new comparison group cannot establish a trend, even though the ledger now has
+two prospective cycles in different groups.
+
+WP-0003 T01 retains delayed history restoration/overlapping navigation ownership and
+interrupted enhancement. WP-0003 T02 retains independent human/AT validation and the
+offline branch. WP-0006 T03 retains comparable-window and remaining review-date work.

research/walkthroughs/VC03-ContentPublication.md

@@ -108,3 +108,12 @@ loss under missing Vary. Validator checks use explicit Node requests. This stren
 the read-only trace; the case remains provisional. Keyboard/focus/announcements, late
 scripts, interrupted transport, invalid/deleted routes and the offline branch remain
 open. No performance, independent-human or decision-usefulness gate is completed.
+
+## Keyboard/feedback subset — 2026-09-27
+
+[NF01–NF06](../reviews/NavigationFocusExperiment.md) exercises keyboard links, request
+failure/recovery, explicit route continuation and a held response after focus moves
+to persistent search. The managed policy passes its DOM obligations; raw same-ID
+focus retention does not itself update title or report errors in this fragment host.
+VC-03 stays provisional. Spoken feedback, focus visibility, delayed history/request
+races and offline availability remain open; no complete accessibility claim.

workplans/FEP-WP-0003-contrasting-schools.md

@@ -201,3 +201,17 @@ WP-0006 T03 remains progress for comparable-window review and remaining substant
 review-date reconciliation. Choose a new comparison group for materially different
 questions. M1/M2 and independent-human validation remain open. See
 research/reviews/NavigationHistoryExperiment.md.
+
+## Measured keyboard/focus cycle — 2026-09-27
+
+LEARN-0012 registered at 2b1c9a4 in new comparison group F-navigation-focus-v1.
+22/22 native/raw/managed rows complete; raw rows are observations, not fulfillment
+of managed obligations. Same-ID focus retained by raw htmx, while authored policy
+adds heading/title/status continuation and preserves newer search focus. Outcome
+corroboration, hypotheses retained; no AT or human validation, no trend across the
+two different prospective groups. See research/reviews/NavigationFocusExperiment.md.
+
+WP-0003 T01 next: delayed history restoration and competing-navigation ownership;
+interrupted/late enhancement remains open. T02 retains AT/independent review and
+offline branch. WP-0006 T03 remains progress for comparable windows and remaining
+review-date reconciliation. No M1/M2 completion.

workplans/FEP-WP-0006-language-evolution.md

@@ -80,3 +80,17 @@ WP-0006 T03 remains progress for comparable-window review and remaining substant
 review-date reconciliation. Choose a new comparison group for materially different
 questions. M1/M2 and independent-human validation remain open. See
 research/reviews/NavigationHistoryExperiment.md.
+
+## Measured keyboard/focus cycle — 2026-09-27
+
+LEARN-0012 registered at 2b1c9a4 in new comparison group F-navigation-focus-v1.
+22/22 native/raw/managed rows complete; raw rows are observations, not fulfillment
+of managed obligations. Same-ID focus retained by raw htmx, while authored policy
+adds heading/title/status continuation and preserves newer search focus. Outcome
+corroboration, hypotheses retained; no AT or human validation, no trend across the
+two different prospective groups. See research/reviews/NavigationFocusExperiment.md.
+
+WP-0003 T01 next: delayed history restoration and competing-navigation ownership;
+interrupted/late enhancement remains open. T02 retains AT/independent review and
+offline branch. WP-0006 T03 remains progress for comparable windows and remaining
+review-date reconciliation. No M1/M2 completion.