refactor: split gsd-tools.test.cjs into domain test files

Move 81 tests (18 describe blocks) from single monolithic test file
into 7 domain-specific test files under tests/ with shared helpers.
Test parity verified: 81/81 pass before and after split.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tests/state.test.cjs

@@ -0,0 +1,156 @@
+/**
+ * GSD Tools Tests - State
+ */
+
+const { test, describe, beforeEach, afterEach } = require('node:test');
+const assert = require('node:assert');
+const fs = require('fs');
+const path = require('path');
+const { runGsdTools, createTempProject, cleanup } = require('./helpers.cjs');
+
+describe('state-snapshot command', () => {
+  let tmpDir;
+
+  beforeEach(() => {
+    tmpDir = createTempProject();
+  });
+
+  afterEach(() => {
+    cleanup(tmpDir);
+  });
+
+  test('missing STATE.md returns error', () => {
+    const result = runGsdTools('state-snapshot', tmpDir);
+    assert.ok(result.success, `Command should succeed: ${result.error}`);
+
+    const output = JSON.parse(result.output);
+    assert.strictEqual(output.error, 'STATE.md not found', 'should report missing file');
+  });
+
+  test('extracts basic fields from STATE.md', () => {
+    fs.writeFileSync(
+      path.join(tmpDir, '.planning', 'STATE.md'),
+      `# Project State
+
+**Current Phase:** 03
+**Current Phase Name:** API Layer
+**Total Phases:** 6
+**Current Plan:** 03-02
+**Total Plans in Phase:** 3
+**Status:** In progress
+**Progress:** 45%
+**Last Activity:** 2024-01-15
+**Last Activity Description:** Completed 03-01-PLAN.md
+`
+    );
+
+    const result = runGsdTools('state-snapshot', tmpDir);
+    assert.ok(result.success, `Command failed: ${result.error}`);
+
+    const output = JSON.parse(result.output);
+    assert.strictEqual(output.current_phase, '03', 'current phase extracted');
+    assert.strictEqual(output.current_phase_name, 'API Layer', 'phase name extracted');
+    assert.strictEqual(output.total_phases, 6, 'total phases extracted');
+    assert.strictEqual(output.current_plan, '03-02', 'current plan extracted');
+    assert.strictEqual(output.total_plans_in_phase, 3, 'total plans extracted');
+    assert.strictEqual(output.status, 'In progress', 'status extracted');
+    assert.strictEqual(output.progress_percent, 45, 'progress extracted');
+    assert.strictEqual(output.last_activity, '2024-01-15', 'last activity date extracted');
+  });
+
+  test('extracts decisions table', () => {
+    fs.writeFileSync(
+      path.join(tmpDir, '.planning', 'STATE.md'),
+      `# Project State
+
+**Current Phase:** 01
+
+## Decisions Made
+
+| Phase | Decision | Rationale |
+|-------|----------|-----------|
+| 01 | Use Prisma | Better DX than raw SQL |
+| 02 | JWT auth | Stateless authentication |
+`
+    );
+
+    const result = runGsdTools('state-snapshot', tmpDir);
+    assert.ok(result.success, `Command failed: ${result.error}`);
+
+    const output = JSON.parse(result.output);
+    assert.strictEqual(output.decisions.length, 2, 'should have 2 decisions');
+    assert.strictEqual(output.decisions[0].phase, '01', 'first decision phase');
+    assert.strictEqual(output.decisions[0].summary, 'Use Prisma', 'first decision summary');
+    assert.strictEqual(output.decisions[0].rationale, 'Better DX than raw SQL', 'first decision rationale');
+  });
+
+  test('extracts blockers list', () => {
+    fs.writeFileSync(
+      path.join(tmpDir, '.planning', 'STATE.md'),
+      `# Project State
+
+**Current Phase:** 03
+
+## Blockers
+
+- Waiting for API credentials
+- Need design review for dashboard
+`
+    );
+
+    const result = runGsdTools('state-snapshot', tmpDir);
+    assert.ok(result.success, `Command failed: ${result.error}`);
+
+    const output = JSON.parse(result.output);
+    assert.deepStrictEqual(output.blockers, [
+      'Waiting for API credentials',
+      'Need design review for dashboard',
+    ], 'blockers extracted');
+  });
+
+  test('extracts session continuity info', () => {
+    fs.writeFileSync(
+      path.join(tmpDir, '.planning', 'STATE.md'),
+      `# Project State
+
+**Current Phase:** 03
+
+## Session
+
+**Last Date:** 2024-01-15
+**Stopped At:** Phase 3, Plan 2, Task 1
+**Resume File:** .planning/phases/03-api/03-02-PLAN.md
+`
+    );
+
+    const result = runGsdTools('state-snapshot', tmpDir);
+    assert.ok(result.success, `Command failed: ${result.error}`);
+
+    const output = JSON.parse(result.output);
+    assert.strictEqual(output.session.last_date, '2024-01-15', 'session date extracted');
+    assert.strictEqual(output.session.stopped_at, 'Phase 3, Plan 2, Task 1', 'stopped at extracted');
+    assert.strictEqual(output.session.resume_file, '.planning/phases/03-api/03-02-PLAN.md', 'resume file extracted');
+  });
+
+  test('handles paused_at field', () => {
+    fs.writeFileSync(
+      path.join(tmpDir, '.planning', 'STATE.md'),
+      `# Project State
+
+**Current Phase:** 03
+**Paused At:** Phase 3, Plan 1, Task 2 - mid-implementation
+`
+    );
+
+    const result = runGsdTools('state-snapshot', tmpDir);
+    assert.ok(result.success, `Command failed: ${result.error}`);
+
+    const output = JSON.parse(result.output);
+    assert.strictEqual(output.paused_at, 'Phase 3, Plan 1, Task 2 - mid-implementation', 'paused_at extracted');
+  });
+});
+
+// ─────────────────────────────────────────────────────────────────────────────
+// summary-extract command
+// ─────────────────────────────────────────────────────────────────────────────
+