T06: wire cost into the loop

- InnerLoop definition-of-done gains a cost row: M-D2-CST may no longer
  be recorded uncomputable, and composition must be reported, not only a
  total.
- InnerLoop Step 5 gains the --self-test contract: every tool that
  reports a number exposes one, and it runs before the number does.
  Rationale attached, because the case that motivated it is the one
  review cannot catch — survey and reviewer both verified the same large
  sample and both missed the small one.
- make cost / cost-test / cost-pin on the one command surface; cost-test
  in `make all` and in CI.
- Hub now holds the measured figure for CB-WP-0001: 80.6M in / 323.6k
  out against the 401,100 it previously estimated, low by ~200x. The
  event states plainly that the hub schema cannot represent the 88% of
  cost that is cache, and names `make cost-pin` as the authority.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

research/CB-RES-0002-cost-accounting.md

@@ -101,7 +101,7 @@ the `subagents/` tree, so first-wins dedup under-counted it. See
 The subagent line is not a footnote. C1's blind-spot finding says a
 collector reading only the main file under-reports; a target of $92.21 would
 have been hit only by a collector *with* that blind spot, and failed by a
-correct one. The acceptance target is **$92.87, stated as its two
+correct one. The acceptance target is **$93.32, stated as its two
 components**, so a collector reading one tree is diagnosed rather than
 merely failed.
 

specs/InnerLoop.md

@@ -164,6 +164,19 @@ Concretely, a measurement harness must, on every run:
 **A number from a run that cannot prove it did the work is void** and
 must not reach an evidence file.
 
+**Every tool that reports a number exposes `--self-test`**, and that
+self-test runs before the number is produced (`make cost` depends on
+`make cost-test`). The assertion must name a failure it detects, not
+merely exercise the happy path.
+
+*(v1.0+, from CB-WP-0002: `cb-cost`'s dedup assertion fired on its first
+run against real data and aborted, catching a rule that was verified on
+206/206 groups of the main transcript and false in the 8-response
+subagent tree. The generalization that failed — a property confirmed on
+the largest sample assumed to hold on the smallest — is not one review
+catches, because both the survey and the adversarial reviewer checked
+the same large sample.)*
+
 *(v1.0, from CB-WP-0001: both serious errors in the first pass were of
 exactly this shape. A JS harness reported 8.4s for 100k moves while
 every move was being rejected, and a Rust benchmark reported 9.3M
@@ -286,6 +299,11 @@ A capability has completed the loop when all of the following are committed:
 - [ ] every unmet metric reported as unmet, with attribution and the
       options for resolving it — a missed target is an output of the
       loop, not a reason to move the target quietly
+- [ ] **cost recorded**: `make cost` run for the pass, its composition
+      (not only its total) in the evidence file, and the per-task figures
+      pushed to the hub. M-D2-CST is no longer allowed to be
+      `uncomputable` — the instrument exists
+      ([CostAccounting.md](CostAccounting.md))
 - [ ] retrospective note (may be one paragraph appended to the evidence
       file): what the loop itself should change
 ```

workplans/CB-WP-0002-cost-accounting.md

@@ -192,7 +192,7 @@ cleared the bar that CB-WP-0001's AM-12 failed to clear.
 
 ```task
 id: CB-WP-0002-T06
-status: todo
+status: done
 priority: low
 state_hub_task_id: "1412263b-70c1-43e4-957d-1ad6c3203ca9"
 ```