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)

tests/workstream-inventory.test.cjs

@@ -11,7 +11,7 @@ const fs = require('fs');
 const path = require('path');
 const { cleanup } = require('./helpers.cjs');
 const { createFixture, seedWorkstream } = require('./fixtures/index.cjs');
-const { buildWorkstreamInventory } = require('../gsd-core/bin/lib/workstream-inventory-builder.cjs');
+const { buildWorkstreamInventory, isCompletedInventory } = require('../gsd-core/bin/lib/workstream-inventory-builder.cjs');
 const { inspectWorkstream } = require('../gsd-core/bin/lib/workstream-inventory.cjs');
 
 const STALE_STATE = 'status: executing\n';
@@ -101,3 +101,26 @@ describe('#1913 — workstream status derived from authoritative shipped signals
     assert.equal(inv.status_conflict, false);
   });
 });
+
+describe('isCompletedInventory — ADR-2207 status lifecycle', () => {
+  test('terminal "milestone complete" variants are completed', () => {
+    assert.ok(isCompletedInventory('1.0 milestone complete'));
+    assert.ok(isCompletedInventory('Milestone complete'));
+    assert.ok(isCompletedInventory('milestone  complete'));
+  });
+
+  test('intermediate "All phases complete" is NOT completed (ADR-2207)', () => {
+    assert.ok(!isCompletedInventory('All phases complete'),
+      'All phases complete is an intermediate state — milestone not yet formally closed');
+  });
+
+  test('archived is completed', () => {
+    assert.ok(isCompletedInventory('archived'));
+  });
+
+  test('active statuses are NOT completed', () => {
+    assert.ok(!isCompletedInventory('Ready to plan'));
+    assert.ok(!isCompletedInventory('In progress'));
+    assert.ok(!isCompletedInventory('Executing'));
+  });
+});