diff --git a/test/skill-coverage-floor.test.ts b/test/skill-coverage-floor.test.ts
new file mode 100644
index 000000000..a0de76292
--- /dev/null
+++ b/test/skill-coverage-floor.test.ts
@@ -0,0 +1,153 @@
+/**
+ * Skill coverage floor — gate-tier, free, runs every PR.
+ *
+ * Phase 0 of the cathedral parity-eval suite: structural-compliance smoke
+ * test that covers every gstack skill with file-IO assertions. The intent
+ * is "every skill ships with at least one CI-blocking check" — even when
+ * a skill doesn't (yet) have a behavioral E2E test, this floor catches
+ * frontmatter regressions, missing generated header, empty/trivial bodies,
+ * and dangling SKILL.md.tmpl-without-SKILL.md mismatches.
+ *
+ * Pairs with test/skill-coverage-matrix.ts (the registry) and
+ * test/parity-suite.test.ts (the content-invariant suite). Together,
+ * v1.45.0.0 ships with: floor (this file) + matrix (registry CI gate)
+ * + invariants (content per skill family) + size budget. That's the
+ * eval-first foundation the v2.0.0.0 sections/ work builds on.
+ */
+
+import { describe, test, expect } from 'bun:test';
+import * as fs from 'fs';
+import * as path from 'path';
+import { SKILL_COVERAGE } from './skill-coverage-matrix';
+
+const REPO_ROOT = path.resolve(import.meta.dir, '..');
+
+function readSkillMd(skill: string): string | null {
+  const p = path.join(REPO_ROOT, skill, 'SKILL.md');
+  try {
+    return fs.readFileSync(p, 'utf-8');
+  } catch {
+    return null;
+  }
+}
+
+function listSkillDirs(): string[] {
+  const entries = fs.readdirSync(REPO_ROOT, { withFileTypes: true });
+  return entries
+    .filter(e => e.isDirectory() && !e.name.startsWith('.'))
+    .filter(e => e.name !== 'node_modules' && e.name !== 'docs' && e.name !== 'test')
+    .filter(e => fs.existsSync(path.join(REPO_ROOT, e.name, 'SKILL.md')))
+    .map(e => e.name)
+    .sort();
+}
+
+describe('skill-coverage-floor: every skill passes structural compliance', () => {
+  const skills = listSkillDirs();
+
+  test('skill registry mentions every skill on disk', () => {
+    const onDisk = new Set(skills);
+    const inRegistry = new Set(Object.keys(SKILL_COVERAGE));
+    const missingFromRegistry: string[] = [];
+    for (const s of onDisk) {
+      if (!inRegistry.has(s)) missingFromRegistry.push(s);
+    }
+    if (missingFromRegistry.length > 0) {
+      throw new Error(
+        `Skills on disk missing from test/skill-coverage-matrix.ts: ${missingFromRegistry.join(', ')}. ` +
+        `Add an entry to SKILL_COVERAGE with at least 'test/skill-coverage-floor.test.ts' in gate[].`,
+      );
+    }
+  });
+
+  test('every registry entry has at least one gate-tier test', () => {
+    const missingGate: string[] = [];
+    for (const [skill, coverage] of Object.entries(SKILL_COVERAGE)) {
+      if (!coverage.gate || coverage.gate.length === 0) missingGate.push(skill);
+    }
+    if (missingGate.length > 0) {
+      throw new Error(
+        `Skills with no gate-tier eval: ${missingGate.join(', ')}. ` +
+        `Eval-first foundation requires at least one CI-blocking check per skill.`,
+      );
+    }
+  });
+
+  test('every gate-tier test path referenced in registry exists on disk', () => {
+    const missing: string[] = [];
+    for (const [skill, coverage] of Object.entries(SKILL_COVERAGE)) {
+      for (const testPath of [...coverage.gate, ...coverage.periodic]) {
+        const fullPath = path.join(REPO_ROOT, testPath);
+        if (!fs.existsSync(fullPath)) {
+          missing.push(`${skill} → ${testPath}`);
+        }
+      }
+    }
+    if (missing.length > 0) {
+      throw new Error(`Registry references missing test files:\n  ${missing.join('\n  ')}`);
+    }
+  });
+
+  // Per-skill structural compliance (file IO only, no LLM)
+  for (const skill of skills) {
+    describe(`skill: ${skill}`, () => {
+      test('SKILL.md exists', () => {
+        const content = readSkillMd(skill);
+        expect(content).not.toBeNull();
+      });
+
+      test('frontmatter is well-formed and contains name + description', () => {
+        const content = readSkillMd(skill)!;
+        expect(content.startsWith('---\n')).toBe(true);
+        const fmEnd = content.indexOf('\n---', 4);
+        expect(fmEnd).toBeGreaterThan(0);
+        const fm = content.slice(4, fmEnd);
+        // name: ...
+        expect(/^name:\s*\S/m.test(fm)).toBe(true);
+        // description: ... (either inline or block form)
+        expect(/^description:\s*(\S|\|)/m.test(fm)).toBe(true);
+      });
+
+      test('frontmatter description fits the catalog-trim contract', () => {
+        const content = readSkillMd(skill)!;
+        const fmEnd = content.indexOf('\n---', 4);
+        const fm = content.slice(4, fmEnd);
+        // Inline form: description: <one line>
+        const inlineMatch = fm.match(/^description:\s+(.+)$/m);
+        // Block form: description: |\n  multiline
+        const blockMatch = fm.match(/^description:\s*\|/m);
+        if (inlineMatch) {
+          // Catalog-trimmed: should be ≤ 250 chars
+          expect(inlineMatch[1].length).toBeLessThanOrEqual(250);
+        } else if (blockMatch) {
+          // Block form is acceptable for small skills (under-120-chars baseline
+          // didn't trigger catalog trim). No size cap here; the parity-suite
+          // and size-budget tests handle bytes.
+        } else {
+          throw new Error(`${skill}: description field is not in inline or block form`);
+        }
+      });
+
+      test('generated header present (only edit .tmpl, not .md)', () => {
+        const content = readSkillMd(skill)!;
+        expect(content).toContain('AUTO-GENERATED from SKILL.md.tmpl');
+      });
+
+      test('body is non-trivial (≥ 200 bytes after frontmatter)', () => {
+        const content = readSkillMd(skill)!;
+        const fmEnd = content.indexOf('\n---', 4);
+        const body = content.slice(fmEnd + 5).trim();
+        expect(body.length).toBeGreaterThanOrEqual(200);
+      });
+
+      test('no unresolved {{TEMPLATE}} placeholders leaked into output', () => {
+        const content = readSkillMd(skill)!;
+        const leaks = content.match(/\{\{[A-Z_]+(?::[^}]+)?\}\}/g);
+        if (leaks) {
+          throw new Error(
+            `${skill}: ${leaks.length} unresolved placeholder(s) in generated SKILL.md: ${leaks.slice(0, 3).join(', ')}${leaks.length > 3 ? ', ...' : ''}`,
+          );
+        }
+      });
+    });
+  }
+});
diff --git a/test/skill-coverage-matrix.test.ts b/test/skill-coverage-matrix.test.ts
new file mode 100644
index 000000000..1c212d456
--- /dev/null
+++ b/test/skill-coverage-matrix.test.ts
@@ -0,0 +1,72 @@
+/**
+ * Skill coverage matrix CI gate (v1.45.0.0 T1).
+ *
+ * Asserts every skill on disk has an entry in SKILL_COVERAGE with at
+ * least one gate-tier test. The detailed per-skill structural checks
+ * live in test/skill-coverage-floor.test.ts; this file is the matrix-
+ * level gate that surfaces "skill added but eval not registered" cleanly.
+ */
+
+import { describe, test, expect } from 'bun:test';
+import * as fs from 'fs';
+import * as path from 'path';
+import { SKILL_COVERAGE, type SkillCoverage } from './skill-coverage-matrix';
+
+const REPO_ROOT = path.resolve(import.meta.dir, '..');
+
+function discoverSkills(): string[] {
+  return fs.readdirSync(REPO_ROOT, { withFileTypes: true })
+    .filter(e => e.isDirectory() && !e.name.startsWith('.'))
+    .filter(e => fs.existsSync(path.join(REPO_ROOT, e.name, 'SKILL.md')))
+    .map(e => e.name)
+    .sort();
+}
+
+describe('skill coverage matrix', () => {
+  test('SKILL_COVERAGE is exported and non-empty', () => {
+    expect(typeof SKILL_COVERAGE).toBe('object');
+    expect(Object.keys(SKILL_COVERAGE).length).toBeGreaterThan(0);
+  });
+
+  test('every entry has the right shape', () => {
+    for (const [skill, coverage] of Object.entries(SKILL_COVERAGE)) {
+      expect(Array.isArray(coverage.gate)).toBe(true);
+      expect(Array.isArray(coverage.periodic)).toBe(true);
+      expect(coverage.gate.length).toBeGreaterThan(0);
+      for (const p of [...coverage.gate, ...coverage.periodic]) {
+        expect(typeof p).toBe('string');
+        expect(p.startsWith('test/')).toBe(true);
+        expect(p.endsWith('.test.ts')).toBe(true);
+      }
+    }
+  });
+
+  test('every skill on disk has a registry entry', () => {
+    const skills = discoverSkills();
+    const missing: string[] = [];
+    for (const s of skills) {
+      if (!SKILL_COVERAGE[s]) missing.push(s);
+    }
+    if (missing.length > 0) {
+      throw new Error(
+        `Skills on disk missing from SKILL_COVERAGE: ${missing.join(', ')}. ` +
+        `Add an entry to test/skill-coverage-matrix.ts with at least ` +
+        `'test/skill-coverage-floor.test.ts' in gate[].`,
+      );
+    }
+  });
+
+  test('no registry entry references a skill that does not exist on disk', () => {
+    const skills = new Set(discoverSkills());
+    const orphans: string[] = [];
+    for (const skill of Object.keys(SKILL_COVERAGE)) {
+      if (!skills.has(skill)) orphans.push(skill);
+    }
+    if (orphans.length > 0) {
+      throw new Error(
+        `Registry references skills not on disk: ${orphans.join(', ')}. ` +
+        `Remove from SKILL_COVERAGE or restore the skill directory.`,
+      );
+    }
+  });
+});
diff --git a/test/skill-coverage-matrix.ts b/test/skill-coverage-matrix.ts
new file mode 100644
index 000000000..2e87e46e4
--- /dev/null
+++ b/test/skill-coverage-matrix.ts
@@ -0,0 +1,181 @@
+/**
+ * Skill coverage matrix (v1.45.0.0 T1, cathedral Phase 0).
+ *
+ * Single source of truth mapping each gstack skill to its E2E test files.
+ * The CI gate at test/skill-coverage-matrix.test.ts fails if a skill has
+ * no gate-tier entry, ensuring the eval-first foundation holds: every
+ * skill has at least one CI-blocking check that asserts must-have
+ * behavior.
+ *
+ * Two tiers per entry:
+ *   gate     CI-blocking, runs on every PR, target <$0.50/test or free.
+ *   periodic Weekly cron, deeper coverage, can cost ~$1-$3/test.
+ *
+ * The 'floor' entry refers to test/skill-coverage-floor.test.ts —
+ * a structural-compliance smoke test that covers every skill with
+ * file-IO checks (free, no LLM cost). When a skill has only 'floor'
+ * coverage, that's the eval-first minimum; future work can layer
+ * behavioral checks on top.
+ */
+
+export interface SkillCoverage {
+  /** Gate-tier test file paths (relative to repo root). At least one required per skill. */
+  gate: string[];
+  /** Periodic-tier test file paths. Optional but recommended. */
+  periodic: string[];
+  /** Brief note on why this coverage is the right shape for this skill. */
+  rationale?: string;
+}
+
+/**
+ * Per-skill coverage. Keys MUST match the top-level skill directory name.
+ * The CI test asserts every skill in the repo has an entry here AND that
+ * gate[] is non-empty.
+ *
+ * Adding a new skill: add an entry here AND either reference an existing
+ * test that covers it OR add 'test/skill-coverage-floor.test.ts' as the
+ * minimum gate-tier check.
+ */
+export const SKILL_COVERAGE: Record<string, SkillCoverage> = {
+  // ─── Core loop ──────────────────────────────────────────────
+  ship: {
+    gate: ['test/skill-e2e-ship-idempotency.test.ts', 'test/skill-coverage-floor.test.ts'],
+    periodic: ['test/skill-e2e-workflow.test.ts'],
+  },
+  review: {
+    gate: ['test/skill-e2e-review.test.ts', 'test/skill-coverage-floor.test.ts'],
+    periodic: ['test/skill-e2e-review-army.test.ts', 'test/regression-1539-review-self-verify.test.ts'],
+  },
+  qa: {
+    gate: ['test/skill-e2e-qa-workflow.test.ts', 'test/skill-coverage-floor.test.ts'],
+    periodic: ['test/skill-e2e-qa-bugs.test.ts'],
+  },
+  'qa-only': {
+    gate: ['test/skill-coverage-floor.test.ts'],
+    periodic: [],
+    rationale: 'qa-only is qa with --report-only; behavior tested via /qa coverage.',
+  },
+  investigate: {
+    gate: ['test/skill-coverage-floor.test.ts'],
+    periodic: [],
+  },
+  browse: {
+    gate: ['test/skill-coverage-floor.test.ts'],
+    periodic: [],
+    rationale: 'browse binary has its own integration suite under browse/test/.',
+  },
+
+  // ─── Plan triad ─────────────────────────────────────────────
+  'plan-ceo-review': {
+    gate: [
+      'test/skill-e2e-plan-ceo-finding-floor.test.ts',
+      'test/skill-e2e-plan-ceo-plan-mode.test.ts',
+      'test/skill-coverage-floor.test.ts',
+    ],
+    periodic: [
+      'test/skill-e2e-plan-ceo-finding-count.test.ts',
+      'test/skill-e2e-plan-ceo-mode-routing.test.ts',
+    ],
+  },
+  'plan-eng-review': {
+    gate: [
+      'test/skill-e2e-plan-eng-finding-floor.test.ts',
+      'test/skill-e2e-plan-eng-plan-mode.test.ts',
+      'test/skill-coverage-floor.test.ts',
+    ],
+    periodic: [
+      'test/skill-e2e-plan-eng-finding-count.test.ts',
+      'test/skill-e2e-plan-eng-multi-finding-batching.test.ts',
+    ],
+  },
+  'plan-design-review': {
+    gate: [
+      'test/skill-e2e-plan-design-finding-floor.test.ts',
+      'test/skill-e2e-plan-design-plan-mode.test.ts',
+      'test/skill-e2e-plan-design-with-ui.test.ts',
+      'test/skill-coverage-floor.test.ts',
+    ],
+    periodic: ['test/skill-e2e-plan-design-finding-count.test.ts'],
+  },
+  'plan-devex-review': {
+    gate: [
+      'test/skill-e2e-plan-devex-finding-floor.test.ts',
+      'test/skill-e2e-plan-devex-plan-mode.test.ts',
+      'test/skill-coverage-floor.test.ts',
+    ],
+    periodic: ['test/skill-e2e-plan-devex-finding-count.test.ts'],
+  },
+  autoplan: {
+    gate: ['test/skill-coverage-floor.test.ts'],
+    periodic: ['test/skill-e2e-autoplan-chain.test.ts', 'test/skill-e2e-autoplan-dual-voice.test.ts'],
+  },
+  'office-hours': {
+    gate: ['test/skill-e2e-office-hours.test.ts', 'test/skill-coverage-floor.test.ts'],
+    periodic: ['test/skill-e2e-office-hours-auto-mode.test.ts', 'test/skill-e2e-office-hours-phase4.test.ts'],
+  },
+
+  // ─── Polish + design ────────────────────────────────────────
+  'design-review': { gate: ['test/skill-coverage-floor.test.ts'], periodic: [] },
+  'design-consultation': { gate: ['test/skill-coverage-floor.test.ts'], periodic: [] },
+  'design-shotgun': { gate: ['test/skill-coverage-floor.test.ts'], periodic: [] },
+  'design-html': { gate: ['test/skill-coverage-floor.test.ts'], periodic: [] },
+  cso: {
+    gate: ['test/skill-e2e-cso.test.ts', 'test/cso-preserved.test.ts', 'test/skill-coverage-floor.test.ts'],
+    periodic: [],
+    rationale: 'cso-preserved.test.ts pins must-not-strip security guidance phrases.',
+  },
+  'document-release': { gate: ['test/skill-coverage-floor.test.ts'], periodic: [] },
+  'document-generate': { gate: ['test/skill-coverage-floor.test.ts'], periodic: [] },
+
+  // ─── Ops + integrations ─────────────────────────────────────
+  'land-and-deploy': { gate: ['test/skill-e2e-deploy.test.ts', 'test/skill-coverage-floor.test.ts'], periodic: [] },
+  canary: { gate: ['test/skill-coverage-floor.test.ts'], periodic: [] },
+  benchmark: { gate: ['test/skill-e2e-benchmark-providers.test.ts', 'test/skill-coverage-floor.test.ts'], periodic: [] },
+  'benchmark-models': { gate: ['test/skill-coverage-floor.test.ts'], periodic: [] },
+  codex: { gate: ['test/skill-coverage-floor.test.ts'], periodic: [] },
+  retro: {
+    gate: ['test/skill-coverage-floor.test.ts'],
+    periodic: ['test/regression-1624-retro-stale-base.test.ts'],
+  },
+  'gstack-upgrade': { gate: ['test/skill-coverage-floor.test.ts'], periodic: [] },
+  'context-save': { gate: ['test/skill-e2e-context-skills.test.ts', 'test/skill-coverage-floor.test.ts'], periodic: [] },
+  'context-restore': { gate: ['test/skill-e2e-context-skills.test.ts', 'test/skill-coverage-floor.test.ts'], periodic: [] },
+  'setup-deploy': { gate: ['test/skill-coverage-floor.test.ts'], periodic: [] },
+  'setup-browser-cookies': { gate: ['test/skill-coverage-floor.test.ts'], periodic: [] },
+  'setup-gbrain': {
+    gate: [
+      'test/skill-e2e-setup-gbrain-bad-token.test.ts',
+      'test/skill-e2e-setup-gbrain-path4-local-pglite.test.ts',
+      'test/skill-e2e-setup-gbrain-remote.test.ts',
+      'test/skill-coverage-floor.test.ts',
+    ],
+    periodic: [],
+  },
+  'sync-gbrain': {
+    gate: ['test/skill-coverage-floor.test.ts'],
+    periodic: ['test/regression-1611-gbrain-sync-resume.test.ts'],
+  },
+  'open-gstack-browser': { gate: ['test/skill-coverage-floor.test.ts'], periodic: [] },
+  'pair-agent': { gate: ['test/skill-coverage-floor.test.ts'], periodic: [] },
+  scrape: { gate: ['test/skill-coverage-floor.test.ts'], periodic: [] },
+  skillify: { gate: ['test/skill-e2e-skillify.test.ts', 'test/skill-coverage-floor.test.ts'], periodic: [] },
+  learn: { gate: ['test/skill-e2e-learnings.test.ts', 'test/skill-coverage-floor.test.ts'], periodic: [] },
+  'plan-tune': { gate: ['test/skill-e2e-plan-tune.test.ts', 'test/skill-coverage-floor.test.ts'], periodic: [] },
+
+  // ─── iOS family ─────────────────────────────────────────────
+  'ios-qa': { gate: ['test/skill-e2e-ios.test.ts', 'test/skill-coverage-floor.test.ts'], periodic: ['test/skill-e2e-ios-device.test.ts', 'test/skill-e2e-ios-swift-build.test.ts'] },
+  'ios-fix': { gate: ['test/skill-coverage-floor.test.ts'], periodic: [] },
+  'ios-clean': { gate: ['test/skill-coverage-floor.test.ts'], periodic: [] },
+  'ios-sync': { gate: ['test/skill-coverage-floor.test.ts'], periodic: [] },
+  'ios-design-review': { gate: ['test/skill-coverage-floor.test.ts'], periodic: [] },
+
+  // ─── Safety / housekeeping ──────────────────────────────────
+  careful: { gate: ['test/skill-coverage-floor.test.ts'], periodic: [] },
+  freeze: { gate: ['test/skill-coverage-floor.test.ts'], periodic: [] },
+  unfreeze: { gate: ['test/skill-coverage-floor.test.ts'], periodic: [] },
+  guard: { gate: ['test/skill-coverage-floor.test.ts'], periodic: [] },
+  'landing-report': { gate: ['test/skill-coverage-floor.test.ts'], periodic: [] },
+  health: { gate: ['test/skill-coverage-floor.test.ts'], periodic: [] },
+  'make-pdf': { gate: ['test/skill-coverage-floor.test.ts'], periodic: [] },
+  'devex-review': { gate: ['test/skill-coverage-floor.test.ts'], periodic: [] },
+};