fix(#2204): phase-completion writes 'All phases complete' per ADR-2207 (#2259)

* fix(#2204): phase-completion writes 'All phases complete' per ADR-2207

completePhaseCore was writing the overloaded bare 'Milestone complete' on the
last phase — the same string space the milestone-close verb owns for terminal
state. Per ADR-2207, phase-completion now writes the existing intermediate
value 'All phases complete' (already used in gsd2-import.cts). Milestone
termination ('<version> milestone complete' / 'Awaiting next milestone')
remains solely with milestoneCompleteCore.

Status lifecycle: Ready to plan → All phases complete → <version> milestone
complete → Awaiting next milestone.

Changes:
- src/state-transition.cts: completePhaseCore status value
- src/phase.cts: #2028 guard comment
- tests/state-transition.test.cjs: assertion + test name
- tests/phase.test.cjs: 8 assertion updates (positive + negative)
- tests/state.test.cjs: normalizeStateStatus test case + reset regex
- tests/workstream.test.cjs: fixture status to terminal value
- gsd-core/workflows/progress.md: Route D label
- gsd-core/workflows/transition.md: Route B label
- CONTEXT.md: Status lifecycle glossary entry (ADR-2207)
- .changeset/brave-geese-jump.md

* test(#2204): regenerate golden-install-parity fixtures + workflow-size baseline

Workflow file edits (progress.md, transition.md) changed install payload
hashes and pushed past the committed workflow-size baseline. Regenerated
all 17 golden-install-parity fixtures + claude-local via the standalone gen
script (which now also covers the local-scope claude layout). Updated
workflow-size-baseline.json and agent-size-baseline.json via size:baseline.

* fix(#2204): correct claude-local golden hashes + document gen-script limitation

The gen-script's claude-local generation produces macOS-specific hashes
incompatible with Linux CI (local-scope install embeds platform-varying
node-runner paths). Reverted to manual update using Linux FAILURES.md
+actual hashes for the 2 changed workflow files. Added explanatory
comment in the gen script.

* test(#2204): add isCompletedInventory coverage + clarify CONTEXT.md glossary

Addresses orthogonal code-review findings (Medium #1 + #2):
- Add isCompletedInventory test cases for ADR-2207 status lifecycle
  (terminal 'milestone complete' → true; intermediate 'All phases
  complete' → false; archived → true; active statuses → false)
- Clarify CONTEXT.md glossary: note that isCompletedInventory
  intentionally excludes the intermediate value

* docs: backfill changeset PR number (#2259)

* docs(#2204): add Status lifecycle table to state-md reference (ADR-2207)

gsd-core/workflows/progress.md

@@ -536,7 +536,7 @@ State: "Current phase is {X}. Milestone has {N} phases (highest: {Y})."
 | Condition | Meaning | Action |
 |-----------|---------|--------|
 | current phase < highest phase | More phases remain | Go to **Route C** |
-| current phase = highest phase | Milestone complete | Go to **Route D** |
+| current phase = highest phase | All phases complete | Go to **Route D** |
 
 ---
 
@@ -602,7 +602,7 @@ NEXT_HAS_UI=$(echo "$NEXT_PHASE_SECTION" | grep -qi "UI hint.*yes" && echo "true
 
 ---
 
-**Route D: Milestone complete**
+**Route D: All phases complete (milestone ready to close)**
 
 ```
 ---