ci: add supply-chain guards — permission allowlist, gitignore rules, manifest checks, pinned actions (#84)

* ci: add supply-chain guards - permission allowlist, gitignore rules, manifest checks, pinned actions

This template's threat model is unusual: it ships pre-approved Claude Code
permissions (.claude/settings.json) and CLI code that every fork user
executes via those permissions. A plausible-looking PR could therefore
ship risk to every forker: widen a permission to Bash(*), weaken the
personal-data gitignore rules, or smuggle code execution into bun install
via a lifecycle script. Nothing checked for these mechanically.

New job security-guards runs tools/security_guards.py (stdlib only):

- settings.json: every permissions.allow entry must be in an exact,
  in-repo allowlist. The guard makes permission changes loud, not
  impossible - a PR that intentionally widens permissions must update
  the allowlist in the same diff, so the widening is explicit and
  reviewable
- .gitignore: the personal-data rules (tracker, documents/**, cv/main_*,
  salary data, seen_jobs) must all still be present - the mirror image
  of the placeholder-integrity job
- .agents/**/package.json: no lifecycle scripts (preinstall/install/
  postinstall/prepare/prepack) and no trustedDependencies, which would
  execute arbitrary code during bun install on users' machines

New job dependency-review (PRs only): actions/dependency-review-action
flags newly introduced vulnerable or malicious dependencies,
fail-on-severity high.

Workflow hardening: explicit top-level permissions: contents: read
(least-privilege token), and all actions pinned to commit SHAs resolved
from the same major tags already in use (checkout v4, setup-python v5,
setup-bun v2), with the tag recorded in a comment.

Honest limit, recorded in the workflow header: a PR can edit this
workflow itself, so these guards catch accidents and casual attempts,
not a determined author. Branch protection with required checks and
human review of workflow/settings diffs remain the real backstop.

Verified locally: positive run passes; injecting Bash(*) into
settings.json, deleting the tracker gitignore rule, and adding a
postinstall script each fail the guard with the intended message, and
reverting restores a clean pass.

* ci: scope dependency-review to upstream PRs - forks lack Dependency graph by default

Verified on a fork: the action fails with 'Dependency review is not
supported on this repository' until Dependency graph is manually enabled,
and forks don't inherit it. Guarded with the same
github.repository == upstream condition the other upstream-only jobs use.
With the graph enabled the action passes, so the config itself is sound.

* ci: probe Dependency graph before dependency-review - warn and pass when unavailable

The upstream PR run showed Dependency graph is disabled on the upstream
repo too (the action hard-fails: 'Dependency review is not supported on
this repository'), not just on forks. Only the repo owner can enable it,
so a hard red X here is friction, not signal.

The job now probes the dependency-graph SBOM endpoint with the workflow
token first: HTTP 200 runs the real review; anything else emits a
::warning:: naming the setting to flip (Settings -> Advanced Security ->
Dependency graph) and passes. Same graceful-skip pattern the workflow
uses for optional tools - the check self-activates the moment the graph
is enabled, no workflow change needed.

.github/workflows/ci.yml

@@ -10,6 +10,16 @@
 # real portals (network-flaky, and the linkedin-search skill is personal-use
 # only per its own ToS warning - CI-automated requests would violate that).
 # CLIs get typechecked instead; live testing stays a local, on-demand step.
+#
+# Security posture: this template ships pre-approved Claude Code permissions
+# and CLI code that every fork user executes, so the security-guards job
+# fails PRs that widen settings.json permissions, weaken the personal-data
+# gitignore rules, or add package lifecycle scripts; dependency-review flags
+# newly introduced vulnerable/malicious dependencies. Honest limit: a PR can
+# edit this workflow itself, so these guards catch accidents and casual
+# attempts, not a determined author - branch protection with required checks
+# and human review of workflow/settings diffs remain the real backstop.
+# Actions are pinned to commit SHAs; the token is read-only.
 
 name: CI
 
@@ -19,24 +29,68 @@ on:
   pull_request:
   workflow_dispatch:
 
+permissions:
+  contents: read
+
 jobs:
   lint:
     name: Lint skills, commands, settings
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-python@v5
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
+      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5
         with:
           python-version: "3.12"
       - run: pip install pyyaml
       - run: python tools/lint_skills.py
 
+  security-guards:
+    name: Security guards (permissions, gitignore, manifests)
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
+      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5
+        with:
+          python-version: "3.12"
+      - run: python tools/security_guards.py
+
+  dependency-review:
+    name: Dependency review (upstream PRs only)
+    # Requires the repo's Dependency graph, which forks never inherit and
+    # which may be disabled upstream - so: upstream PRs only, and the
+    # graph is probed first. If it is unavailable, the job warns and
+    # passes instead of hard-failing (the same graceful-skip pattern the
+    # workflow uses for optional tools). Enabling Dependency graph under
+    # Settings -> Advanced Security activates the real check.
+    if: github.event_name == 'pull_request' && github.repository == 'MadsLorentzen/ai-job-search'
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
+      - name: Probe Dependency graph availability
+        id: graph
+        run: |
+          code=$(curl -s -o /dev/null -w "%{http_code}" \
+            -H "Authorization: Bearer ${{ github.token }}" \
+            -H "Accept: application/vnd.github+json" \
+            "https://api.github.com/repos/${{ github.repository }}/dependency-graph/sbom")
+          if [ "$code" = "200" ]; then
+            echo "enabled=true" >> "$GITHUB_OUTPUT"
+          else
+            echo "enabled=false" >> "$GITHUB_OUTPUT"
+            echo "::warning::Dependency graph is not enabled on this repository (HTTP $code). Dependency review was skipped - enable Dependency graph under Settings -> Advanced Security to activate this check."
+          fi
+      - name: Dependency review
+        if: steps.graph.outputs.enabled == 'true'
+        uses: actions/dependency-review-action@2031cfc080254a8a887f58cffee85186f0e49e48 # v4.9.0
+        with:
+          fail-on-severity: high
+
   latex-smoke:
     name: Compile example CV and cover letter
     runs-on: ubuntu-latest
     container: texlive/texlive:latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
       - name: Compile CV example (lualatex)
         run: |
           cd cv
@@ -78,8 +132,8 @@ jobs:
           - jobnet-search
           - linkedin-search
     steps:
-      - uses: actions/checkout@v4
-      - uses: oven-sh/setup-bun@v2
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
+      - uses: oven-sh/setup-bun@0c5077e51419868618aeaa5fe8019c62421857d6 # v2
       - run: bun install
         working-directory: .agents/skills/${{ matrix.tool }}/cli
       - run: bun run typecheck
@@ -90,7 +144,7 @@ jobs:
     if: github.repository == 'MadsLorentzen/ai-job-search'
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
       - name: Tracked template files must keep their placeholder tokens
         run: |
           fail=0