MAS-WP-0005-T09: generator destination transforms with round-trip refusal; example profiles

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Assistant: claude-code
Assistant-Model: opus
Assistant-Process: 252470@bnt-lap001
Assistant-Session: ad628c8f-4be2-4979-94c9-76c7ed6f8241

workplans/MAS-WP-0005-spec-errata-v0-1-1.md

@@ -293,7 +293,7 @@ the stand-in constraints. Statute-aware fixtures.
 
 ```task
 id: MAS-WP-0005-T09
-status: todo
+status: done
 priority: medium
 state_hub_task_id: "853d1b76-8b7f-5234-aacc-dc1fb5d155c2"
 ```
@@ -303,6 +303,25 @@ canonical form when allowed; refuse when the namespace would not accept the
 result; re-check the length after transforms. Include an example destination
 profile `ionos-forward`. This is the base for the composer (MAS-WP-0006).
 
+- 2026-10-18 done: `mas_core.generator.for_destination(local_part, statute,
+  needs, allow_lossy=False)` returns `DestinationAddress(local_part, applied,
+  warnings)`.
+  - It applies only the transforms that change something.
+  - Lossy transforms need `allow_lossy`; `drop-interaction` adds a warning.
+  - Refusals raise `CannotExpress`: `transform-not-permitted` (statute
+    switch off, or a v0.1 statute), `cannot-express` (id contains `=`),
+    `too-long` (after transforms) and `would-be-misread`.
+  - Safety is a round trip: the result is resolved with the receiving
+    policy and must give the same equivalence key, facet and interaction.
+    This catches lower-casing under `resource_id_case: exact` and case
+    changes in facets.
+  - Example profiles: `canonical`, `ionos-forward` (resource-alternate +
+    lowercase), `google-groups` (lowercase).
+  - 11 new tests; 179 pass.
+  - Correction: there is no `mas generate` CLI command. The review's gate
+    table and MAS-WP-0006 now point to `for_destination`; the CLI/UI is
+    MAS-WP-0006.
+
 ## v0.2 live check: IONOS forward with stand-ins
 
 ```task

workplans/MAS-WP-0006-address-composer.md

@@ -35,7 +35,8 @@ Define what the composer does: from a statute and an intent (resource,
 facet, interaction), emit the canonical address and, when the statute
 declares one, the forwarder-safe form (lower case, `--` separator). Warn
 about the 64-octet budget and facet/interaction exclusivity. Decide
-whether it is an extension of `mas generate`, a web page, or both.
+whether it is a new CLI command (the CLI has no generate command yet), a web page,
+or both. The library side exists: `mas_core.generator.for_destination` (MAS-WP-0005 T09).
 
 ## Implement and test