enhance(#3883): route every slug call site through its canonical owner (#3896)

* docs(#3883): correct section 8.3 against the tree

I wrote this section in Phase 0 stating rules I had not executed against the
tree. Measured at 832dcbb75, three statements are wrong.

The slug count is 11 across 5 files, not 13; two of the thirteen were an
unrelated tokenizer regex. The divergence is real and reproduced.

resolveRuntime reads no install marker at all and has no cache; PR #3382,
cited as prior art for that rung, is closed unmerged.

The Codex sandbox is still a hand-maintained subset map with a silent
read-only fallback, and validate agents checks file presence only -- both
halves of that claim are false.

The shortFormToId rule is accurate. The guard roster names no casualty for
this rule.

Section 8.3 is therefore a work list, not a conformance check.

Refs #3883

* test(#3883): failing-first rows for slug re-implementation divergence

Refs #3883

* feat(#3883): route every slug call site through its canonical owner

Migrated commands.cts:209, init.cts:176/1935/1957/3109, phase-id.cts:229/380, phase-locator.cts:269, workstream-name-policy.cts:75 to generateSlugInternal (core-utils.cts:107).

Declared different: gsd2-import.cts:97 (no truncation), active-workstream-store.cts:97 (fixed ASCII env-key domain, already matches).

Fixed a latent circular-require bug: core-utils.cts top-level destructured comparePhaseNum/scopeToPhase from phase-id.cjs; switched both sides of the new circular require to lazy function-body requires.

Refs #3883

* fix(#3883): restore per-site truncation contracts broken by the slug consolidation

Refs #3883

* fix(#3883): close review findings — changeset, miscounts, loose rows, cyclic destructure

Refs #3883

* docs(#3883): correct the same slug miscount in the Context table

Section 8.3's rule text was corrected to 11 copies across 7 files; the Context
table above it still carried the original 13 across 5. Same wrong claim, second
location, both mine.

Refs #3883

* chore(#3883): backfill changeset PR number

Refs #3883

* test(#3883): keep the core-utils mutation shard inside its time budget

PR #3896's Stryker (core-utils) shard was cancelled at the 15-minute
shard cap. Stryker's command-runner bills one `node --test <file>`
invocation as a single unit costing whatever the file's slowest run
costs, re-run once per mutant (documented in
tests/state-contract.test.cjs's header, #2790 precedent). A3/A5 drove
every CLI-reachable slug site through runGsdTools (a real child-process
spawn per call, ~85-170ms each across ~70 calls), accounting for ~7.1s
of the file's ~7.9s wall time.

commands.cts:cmdGenerateSlug and init.cts:cmdInitExecutePhase/
cmdInitPhaseOp/cmdInitProgress are plain functions reachable in-process
from the built gsd-core/bin/lib/*.cjs, so this calls them directly
instead of spawning gsd-tools, capturing their fd-1 JSON output with the
bug #1008 fs.writeSync-mock pattern already used in tests/io.test.cjs
and tests/init.test.cjs. A hermetic-env helper reproduces the isolation
runGsdTools's { HOME: tmpDir } + testEnvBase() gave the child process.

File wall time drops from ~7.97s to ~1.1s (246/246 passing, same
coverage), well inside the 15-minute cap even at hundreds of mutants.

Refs #3883

---------

Co-authored-by: sim <sim@local>

src/init.cts

@@ -174,9 +174,12 @@ function guardedGetRoadmapPhase(
 // directory exists yet) identically at every synthetic-fallback call site
 // below — factored out once so the slugification formula itself cannot drift.
 function slugifyPhaseName(phaseName: string | null): string | null {
-  return phaseName
-    ? phaseName.toLowerCase().replace(/[^a-z0-9]+/g, '-').replace(/^-+|-+$/g, '')
-    : null;
+  // #3883 (ADR-3473 §8.3): delegate to the canonical slug formula
+  // (generateSlugInternal, core-utils.cts) rather than re-implementing it.
+  // `maxLen: null` preserves this site's pre-migration untruncated contract —
+  // the 60-char default would collapse two distinct >60-char phase names onto
+  // the same reported phase_slug.
+  return phaseName ? coreUtils.generateSlugInternal(phaseName, null) : null;
 }
 
 /**
@@ -1931,9 +1934,11 @@ function cmdInitPhaseOp(cwd: string, phase: string, raw: boolean): void {
         directory: null,
         phase_number: roadmapPhase['phase_number'],
         phase_name: phaseName,
-        phase_slug: phaseName
-          ? phaseName.toLowerCase().replace(/[^a-z0-9]+/g, '-').replace(/^-+|-+$/g, '')
-          : null,
+        // #3883 (ADR-3473 §8.3): delegate to the canonical slug formula
+        // (generateSlugInternal, core-utils.cts) rather than re-implementing
+        // it. `maxLen: null` preserves this site's pre-migration untruncated
+        // contract.
+        phase_slug: phaseName ? coreUtils.generateSlugInternal(phaseName, null) : null,
         plans: [],
         summaries: [],
         incomplete_plans: [],
@@ -1953,9 +1958,11 @@ function cmdInitPhaseOp(cwd: string, phase: string, raw: boolean): void {
         directory: null,
         phase_number: roadmapPhase['phase_number'],
         phase_name: phaseName,
-        phase_slug: phaseName
-          ? phaseName.toLowerCase().replace(/[^a-z0-9]+/g, '-').replace(/^-+|-+$/g, '')
-          : null,
+        // #3883 (ADR-3473 §8.3): delegate to the canonical slug formula
+        // (generateSlugInternal, core-utils.cts) rather than re-implementing
+        // it. `maxLen: null` preserves this site's pre-migration untruncated
+        // contract.
+        phase_slug: phaseName ? coreUtils.generateSlugInternal(phaseName, null) : null,
         plans: [],
         summaries: [],
         incomplete_plans: [],
@@ -3111,7 +3118,11 @@ function cmdInitProgress(cwd: string, raw: boolean, options: Record<string, unkn
       const status = 'not_started';
       const phaseInfo: Record<string, unknown> = {
         number: num,
-        name: name.toLowerCase().replace(/[^a-z0-9]+/g, '-').replace(/^-+|-+$/g, ''),
+        // #3883 (ADR-3473 §8.3): delegate to the canonical slug formula
+        // (generateSlugInternal, core-utils.cts) rather than re-implementing
+        // it. `maxLen: null` preserves this site's pre-migration untruncated
+        // contract.
+        name: coreUtils.generateSlugInternal(name, null) ?? '',
         directory: null,
         status,
         plan_count: 0,