fix(#3576): repair all 43 dead references/ cites and gate the canonical resolvable form (#3596)

* test(#3576): gate shipped reference citations on the canonical resolvable form

Failing-first gate for #3576: a backticked bare references/<name>.md cite
resolves from no install location (agents, workflows, and references all
install where a bare relative references/ path is dead). The gate walks the
runtime-loaded trees the issue prescribes, strips @~/ include tokens
PER-TOKEN (a line-skip guard would miss a bare cite sharing a line with an
include — the issue-named trap), pins the genuinely relative ../ href and
canonical forms as non-offenders, and checks canonical cite targets exist.
43 offenders today across 19 files.

* fix(#3576): repair all 43 dead references/ cites to the canonical resolvable form

Every backticked bare references/<name>.md cite across the 19 shipped files
rewritten to gsd-core/references/<name>.md — the form every required_reading
block and @~/ include already uses, and the only form that resolves from any
install location. All 20 cited targets verified to exist; the one genuinely
relative href (plan-phase.md's ../references/mvp-concepts.md) is untouched
(the repair is backtick-anchored). Growth acks: new fragment for the three
first-time paths, #3206-pattern appends to the five fragments already naming
the other grown files (two ack sources may never name the same path).
execute-phase.md lands at 93,391/93,400 and gsd-executor.md at 49,150/49,152
— exactly the issue's projections; every repair fits.

* fix(#3576): drop stale default.md growth ack (nested modes file is hash-attributed, not growth-ratcheted)

Review finding: the emitted-attribution ratchet covers only top-level
workflows/ + agents/ files; discuss-phase/modes/default.md's delta is
source-attributed, so acknowledging its growth is a stale entry the
differential lane fails on.

* chore(#3576): add changeset fragment

* chore(#3576): backfill changeset pr number

---------

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

gsd-core/workflows/plan-phase.md

@@ -90,7 +90,7 @@ CONTEXT_WINDOW=$(gsd_run query config-get context_window 2>/dev/null || echo "20
 MVP_MODE_CFG=$(gsd_run query config-get workflow.mvp_mode 2>/dev/null || echo "false")
 ```
 
-When the tdd capability's `workflow.tdd_mode` is active (resolved via the plan:pre render-hooks), the planner agent is instructed to apply `type: tdd` to eligible tasks using heuristics from `references/tdd.md`. The TDD guidance is injected via the tdd capability's contribution hook at §5.6; no inline config-get is needed.
+When the tdd capability's `workflow.tdd_mode` is active (resolved via the plan:pre render-hooks), the planner agent is instructed to apply `type: tdd` to eligible tasks using heuristics from `gsd-core/references/tdd.md`. The TDD guidance is injected via the tdd capability's contribution hook at §5.6; no inline config-get is needed.
 
 When `CONTEXT_WINDOW >= 500000`, the planner prompt includes the 3 most recent prior-phase CONTEXT.md/SUMMARY.md files plus any phases in the current phase's `Depends on:` field (explicit deps load regardless of recency).
 
@@ -168,7 +168,7 @@ When `WALKING_SKELETON=true`:
 - Planner is instructed to produce `SKELETON.md` in the phase directory alongside `PLAN.md`. The template lives at `~/.claude/gsd-core/references/skeleton-template.md` — the planner reads it when producing SKELETON.md (lazy; not loaded on non-skeleton runs).
 - The plan must scaffold project + routing + one real DB read/write + one real UI interaction + dev deployment — the thinnest possible end-to-end working slice.
 
-**Interaction with `--prd <filepath>`.** `--mvp` and `--prd` compose. The PRD express path (Step 3.5) creates `CONTEXT.md` from the PRD file and continues to research; the Walking Skeleton gate fires independently from the conditions above. When both are active on Phase 1 of a new project, the planner receives `WALKING_SKELETON=true` and PRD-derived context simultaneously — the PRD informs *what the skeleton should prove*. No precedence is needed; the two signals are orthogonal. See [`references/mvp-concepts.md`](../references/mvp-concepts.md) for the broader interaction map.
+**Interaction with `--prd <filepath>`.** `--mvp` and `--prd` compose. The PRD express path (Step 3.5) creates `CONTEXT.md` from the PRD file and continues to research; the Walking Skeleton gate fires independently from the conditions above. When both are active on Phase 1 of a new project, the planner receives `WALKING_SKELETON=true` and PRD-derived context simultaneously — the PRD informs *what the skeleton should prove*. No precedence is needed; the two signals are orthogonal. See [`gsd-core/references/mvp-concepts.md`](../references/mvp-concepts.md) for the broader interaction map.
 
 Extract express-path args from $ARGUMENTS: `PRD_FILE` (`--prd <filepath>`), `INGEST_PATH` (`--ingest <path-or-glob>`), and optional `INGEST_FORMAT` (`--ingest-format <auto|nygard|madr|narrative>`, default `auto`).
 
@@ -784,7 +784,7 @@ Output consumed by /gsd:execute-phase. Plans need:
 - Tasks in XML format with read_first and acceptance_criteria fields (MANDATORY on every task)
 - Verification criteria
 - must_haves for goal-backward verification
-- If the SPEC has an `## Edge Coverage` section, lift every resolved (verification: explicit) edge's acceptance criterion into `must_haves.truths` as a plain string, and every resolved (verification: backstop) edge **as a structured flat-scalar marker** — an object item `{ statement: <the check>, verification: backstop }`, NOT a prose note (the verifier branches deterministically on the `verification: backstop` field; a parenthetical is unparseable — the #1110 fragility). Use a flat scalar `verification:` continuation key, never a nested object (ADR-550 #1278). At verify time a `backstop` truth the verifier cannot confirm with explicit evidence abstains → `human_needed` (reason `insufficient_spec`), never a silent pass (#1154; see `references/honest-verifier.md`). `unresolved` edges are explicit assumptions — surface them in the plan, do not silently drop them. **Otherwise** (`EDGE_ABSENT`): apply the SAME lift to the fallback report `{COVERAGE}` (per §C of `references/specless-probe-fallback.md`); a SPEC-supplied section is never re-run.
+- If the SPEC has an `## Edge Coverage` section, lift every resolved (verification: explicit) edge's acceptance criterion into `must_haves.truths` as a plain string, and every resolved (verification: backstop) edge **as a structured flat-scalar marker** — an object item `{ statement: <the check>, verification: backstop }`, NOT a prose note (the verifier branches deterministically on the `verification: backstop` field; a parenthetical is unparseable — the #1110 fragility). Use a flat scalar `verification:` continuation key, never a nested object (ADR-550 #1278). At verify time a `backstop` truth the verifier cannot confirm with explicit evidence abstains → `human_needed` (reason `insufficient_spec`), never a silent pass (#1154; see `gsd-core/references/honest-verifier.md`). `unresolved` edges are explicit assumptions — surface them in the plan, do not silently drop them. **Otherwise** (`EDGE_ABSENT`): apply the SAME lift to the fallback report `{COVERAGE}` (per §C of `gsd-core/references/specless-probe-fallback.md`); a SPEC-supplied section is never re-run.
 - If the SPEC has a `## Prohibitions` section, lift every resolved prohibition into the `must_haves.prohibitions:` sibling block (NOT `truths` — ADR-550 D3) with `statement`+`status`+`verification`, via the single `projectProhibitions` serializer (Hyrum — no second serializer); unresolved -> flagged assumptions, don't drop; never put a must-NOT under `truths`. **Otherwise** (`PROHIB_ABSENT`), author the recalled prohibitions into the SAME block via the SAME `projectProhibitions` contract but **descriptor-less** (no `check_*`) so each disposes flagged-unverified; never auto-dismiss. Section-level precedence + no-silent-drop equality apply (§C).
 - If a `-UI-SPEC.md` exists (resolved above as `UI_SPEC_PATH`) with a `## UI Considerations` section, lift it by the **identical rule** as `## Edge Coverage` above — resolved (explicit) → `must_haves.truths` string, resolved (backstop) → flat scalar `{ statement, verification: backstop }`, `unresolved` → explicit planner assumption (no new verb — ADR-550 #1278/#1154; #1867). Read it from `UI_SPEC_PATH` (the SPEC glob excludes `-UI-SPEC.md`).
 - **"Artifacts this phase produces" section (MANDATORY)** — list every symbol this phase creates: decorators, classes, functions, CLI flags, struct/dataclass fields, new file paths. The plan-review-convergence source-grounding pass reads this section to exclude newly-created symbols from drift verification; omitting it causes new symbols to be flagged for acknowledgement.