refactor: extract composite actions for eval-lane setup; surviving lanes gain the fail-fast registry verification

'Fix bun temp' x3, 'Restore deps' x5, 'Seed claude interactive config' x3,
and 'Register gstack skills' x3 were byte-near-identical copies across the
legacy matrix, the sliced lane, and the periodic lane — and only the MATRIX
copy of register-skills carried the 19-line dangling-symlink + frontmatter
fail-fast loop written after a silent 'Unknown command' + 35-min-timeout
incident. Extract all four into .github/actions/ composites; the register
composite carries the verification loop (generalized over the skill list),
so the sliced and periodic lanes — the lanes that SURVIVE the matrix
deletion — now inherit the check they had silently dropped. Matrix-job
inline copies are left untouched: that job is deleted next.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.github/actions/fix-bun-temp/action.yml

@@ -0,0 +1,18 @@
+name: Fix bun temp
+description: >
+  Redirect bun's cache/temp to a runner-writable dir. Bun creates root-owned
+  temp dirs during the Docker image build; GH Actions runs container jobs as
+  the `runner` user with HOME=/github/home, so without this redirect bun hits
+  EACCES on its default temp paths. Shared by every eval lane — extracted from
+  three byte-identical copies (legacy matrix, sliced lane, periodic).
+runs:
+  using: composite
+  steps:
+    - shell: bash
+      run: |
+        mkdir -p /home/runner/.cache/bun
+        {
+          echo "BUN_INSTALL_CACHE_DIR=/home/runner/.cache/bun"
+          echo "BUN_TMPDIR=/home/runner/.cache/bun"
+          echo "TMPDIR=/home/runner/.cache"
+        } >> "$GITHUB_ENV"

.github/actions/register-gstack-skills/action.yml

@@ -0,0 +1,98 @@
+name: Register gstack skills for PTY tests
+description: >
+  Register the skills PTY smokes invoke, in every place claude looks:
+  user-scoped ($HOME/.claude/skills — a gstack root symlink for the
+  preamble's absolute runtime paths, plus per-skill REAL-FILE copies because
+  claude's interactive-TUI skill scanner does not follow the
+  /github/home -> /__w cross-mount symlink), and project-scoped
+  (<repo>/.claude/skills, which the TUI reads for /slash commands and which
+  is gitignored so absent on a fresh CI checkout). Also pre-seeds every
+  one-time preamble marker so no PTY child takes a first-run branch mid-test
+  (feature discovery under ~/.claude/skills/gstack trips Claude Code's
+  sensitive-file permission prompt — the documented intermittent
+  scope-gate-question-NOT-observed failure).
+
+  Ends with the fail-fast verification loop the legacy matrix copy grew
+  after a silent "Unknown command" + 35-min-timeout incident: a dangling
+  symlink or renamed committed target fails HERE, in seconds, with a named
+  path — never as a wedged PTY session at the shard wall. Every consuming
+  lane inherits the loop by construction (it previously existed only in the
+  matrix copy; the sliced + periodic copies had silently dropped it).
+inputs:
+  skills:
+    description: Space-separated skill dirs (each must have SKILL.md + sections/).
+    required: false
+    default: office-hours plan-ceo-review plan-eng-review plan-design-review
+runs:
+  using: composite
+  steps:
+    - shell: bash
+      env:
+        SKILLS: ${{ inputs.skills }}
+      run: |
+        set -eu
+        SKILLS_DIR="$HOME/.claude/skills"
+        REPO="$GITHUB_WORKSPACE"
+        mkdir -p "$SKILLS_DIR"
+        # The gstack root stays a symlink — the preamble's runtime bash resolves
+        # ~/.claude/skills/gstack/bin/* and ~/.claude/skills/gstack/<skill>/sections/*
+        # through it, and bash follows cross-mount symlinks fine.
+        ln -snf "$REPO" "$SKILLS_DIR/gstack"
+        for s in $SKILLS; do
+          rm -rf "${SKILLS_DIR:?}/$s"
+          mkdir -p "$SKILLS_DIR/$s"
+          cp "$REPO/$s/SKILL.md" "$SKILLS_DIR/$s/SKILL.md"
+          cp -R "$REPO/$s/sections" "$SKILLS_DIR/$s/sections"
+        done
+        PROJ_SKILLS="$REPO/.claude/skills"
+        mkdir -p "$PROJ_SKILLS"
+        for s in $SKILLS; do
+          rm -rf "${PROJ_SKILLS:?}/$s"
+          mkdir -p "$PROJ_SKILLS/$s"
+          cp "$REPO/$s/SKILL.md" "$PROJ_SKILLS/$s/SKILL.md"
+          cp -R "$REPO/$s/sections" "$PROJ_SKILLS/$s/sections"
+        done
+        # Pre-seed every ONE-TIME preamble marker so no PTY child ever takes a
+        # first-run branch mid-test.
+        mkdir -p "$HOME/.gstack"
+        touch "$HOME/.gstack/.activated" \
+              "$HOME/.gstack/.first-loop-tip-shown" \
+              "$HOME/.gstack/.telemetry-prompted" \
+              "$HOME/.gstack/.proactive-prompted" \
+              "$HOME/.gstack/.completeness-intro-seen" \
+              "$HOME/.gstack/.plan-tune-nudge-shown"
+        # These two resolve through the gstack root symlink into $REPO —
+        # untracked scratch in the CI checkout, exactly where the preamble looks.
+        touch "$SKILLS_DIR/gstack/.feature-prompted-continuous-checkpoint" \
+              "$SKILLS_DIR/gstack/.feature-prompted-model-overlay"
+        echo "--- registry under $SKILLS_DIR ---"
+        ls -la "$SKILLS_DIR/gstack"
+        # ── Fail-fast verification ──────────────────────────────────────────
+        # A dangling symlink or moved/renamed committed target must fail here
+        # with a named path, not resurface as a silent "Unknown command" and a
+        # PTY session wedged to its wall timeout.
+        for f in \
+          "$SKILLS_DIR/gstack/bin/gstack-update-check" \
+          "$SKILLS_DIR/gstack/scripts/gen-skill-docs.ts"; do
+          if [ ! -e "$f" ]; then
+            echo "ERROR: gstack root symlink dangles or target moved: $f" >&2
+            exit 1
+          fi
+        done
+        for s in $SKILLS; do
+          if [ ! -e "$SKILLS_DIR/$s/SKILL.md" ]; then
+            echo "ERROR: skill-registry target missing: $SKILLS_DIR/$s/SKILL.md" >&2
+            exit 1
+          fi
+          grep -m1 "^name: $s\$" "$SKILLS_DIR/$s/SKILL.md" >/dev/null \
+            || { echo "ERROR: $s SKILL.md missing 'name: $s' frontmatter" >&2; exit 1; }
+          # Sections must exist BOTH as the copied real files (TUI reads) and
+          # through the gstack root symlink (the preamble's runtime paths).
+          for d in "$SKILLS_DIR/$s/sections" "$SKILLS_DIR/gstack/$s/sections"; do
+            if [ ! -d "$d" ] || [ -z "$(ls -A "$d")" ]; then
+              echo "ERROR: skill sections missing or empty: $d" >&2
+              exit 1
+            fi
+          done
+        done
+        echo "skill registry OK"

.github/actions/restore-deps/action.yml

@@ -0,0 +1,19 @@
+name: Restore deps
+description: >
+  Restore the CI image's pre-installed node_modules via recursive copy, or
+  fall back to bun install when the lockfile changed. Symlinking breaks bun's
+  realpath-based module resolution (realpath escapes the workspace and
+  sibling deps stop resolving); hardlink copy fails across overlay-fs layers
+  ("Invalid cross-device link"). Recursive copy costs ~5s for ~200 packages —
+  still far cheaper than a network install. Extracted from five byte-similar
+  copies across the eval lanes.
+runs:
+  using: composite
+  steps:
+    - shell: bash
+      run: |
+        if [ -d /opt/node_modules_cache ] && diff -q /opt/node_modules_cache/.bun.lock bun.lock >/dev/null 2>&1; then
+          cp -r /opt/node_modules_cache node_modules
+        else
+          bun install
+        fi

.github/actions/seed-claude-config/action.yml

@@ -0,0 +1,30 @@
+name: Seed claude interactive config
+description: >
+  Seed ~/.claude.json with onboarding-complete plus the API-key approval so
+  PTY sessions never wedge on the fresh-container onboarding / "use detected
+  ANTHROPIC_API_KEY?" dialog. Mirrors what the hermetic E2E child env seeds.
+  Idempotent — safe to run unconditionally in sliced lanes where any slice
+  can host a PTY test. Only the key's last 20 chars are persisted (the
+  approval-hash form claude itself writes), never the whole key.
+inputs:
+  anthropic-api-key:
+    description: API key whose suffix gets pre-approved. Pass from secrets at the call site.
+    required: false
+    default: ''
+runs:
+  using: composite
+  steps:
+    - shell: bash
+      env:
+        ANTHROPIC_API_KEY: ${{ inputs.anthropic-api-key }}
+      run: |
+        node -e '
+          const fs = require("fs"), os = require("os"), path = require("path");
+          const p = path.join(os.homedir(), ".claude.json");
+          const seed = fs.existsSync(p) ? JSON.parse(fs.readFileSync(p, "utf8")) : {};
+          seed.hasCompletedOnboarding = true;
+          const key = process.env.ANTHROPIC_API_KEY || "";
+          if (key) seed.customApiKeyResponses = { approved: [key.slice(-20)], rejected: [] };
+          fs.writeFileSync(p, JSON.stringify(seed, null, 2));
+          console.log("seeded", p);
+        '

.github/workflows/evals-periodic.yml

@@ -95,12 +95,7 @@ jobs:
           persist-credentials: false
 
       - name: Restore deps
-        run: |
-          if [ -d /opt/node_modules_cache ] && diff -q /opt/node_modules_cache/.bun.lock bun.lock >/dev/null 2>&1; then
-            cp -r /opt/node_modules_cache node_modules
-          else
-            bun install
-          fi
+        uses: ./.github/actions/restore-deps
 
       - name: Emit run manifest (ALL periodic tests minus reasoned excludes)
         env:
@@ -144,71 +139,25 @@ jobs:
           persist-credentials: false
 
       - name: Fix bun temp
-        run: |
-          mkdir -p /home/runner/.cache/bun
-          {
-            echo "BUN_INSTALL_CACHE_DIR=/home/runner/.cache/bun"
-            echo "BUN_TMPDIR=/home/runner/.cache/bun"
-            echo "TMPDIR=/home/runner/.cache"
-          } >> "$GITHUB_ENV"
+        uses: ./.github/actions/fix-bun-temp
 
       - name: Restore deps
-        run: |
-          if [ -d /opt/node_modules_cache ] && diff -q /opt/node_modules_cache/.bun.lock bun.lock >/dev/null 2>&1; then
-            cp -r /opt/node_modules_cache node_modules
-          else
-            bun install
-          fi
+        uses: ./.github/actions/restore-deps
 
       - run: bun run build
 
       # Any slice can host a PTY test — seed + registration run
-      # unconditionally (idempotent; mirrors evals.yml's sliced lane).
+      # unconditionally (idempotent; mirrors evals.yml's sliced lane). The
+      # register composite carries the fail-fast dangling-symlink/frontmatter
+      # verification loop — this lane previously LACKED it, so a moved skill
+      # target surfaced as a silent "Unknown command" + wedged PTY session.
       - name: Seed claude interactive config
-        env:
-          ANTHROPIC_API_KEY: ${{ secrets.ANTHROPIC_API_KEY }}
-        run: |
-          node -e '
-            const fs = require("fs"), os = require("os"), path = require("path");
-            const p = path.join(os.homedir(), ".claude.json");
-            const seed = fs.existsSync(p) ? JSON.parse(fs.readFileSync(p, "utf8")) : {};
-            seed.hasCompletedOnboarding = true;
-            const key = process.env.ANTHROPIC_API_KEY || "";
-            if (key) seed.customApiKeyResponses = { approved: [key.slice(-20)], rejected: [] };
-            fs.writeFileSync(p, JSON.stringify(seed, null, 2));
-            console.log("seeded", p);
-          '
+        uses: ./.github/actions/seed-claude-config
+        with:
+          anthropic-api-key: ${{ secrets.ANTHROPIC_API_KEY }}
 
       - name: Register gstack skills for PTY tests
-        run: |
-          set -eu
-          SKILLS_DIR="$HOME/.claude/skills"
-          REPO="$GITHUB_WORKSPACE"
-          mkdir -p "$SKILLS_DIR"
-          ln -snf "$REPO" "$SKILLS_DIR/gstack"
-          for s in office-hours plan-ceo-review plan-eng-review plan-design-review; do
-            rm -rf "${SKILLS_DIR:?}/$s"
-            mkdir -p "$SKILLS_DIR/$s"
-            cp "$REPO/$s/SKILL.md" "$SKILLS_DIR/$s/SKILL.md"
-            cp -R "$REPO/$s/sections" "$SKILLS_DIR/$s/sections"
-          done
-          PROJ_SKILLS="$REPO/.claude/skills"
-          mkdir -p "$PROJ_SKILLS"
-          for s in office-hours plan-ceo-review plan-eng-review plan-design-review; do
-            rm -rf "${PROJ_SKILLS:?}/$s"
-            mkdir -p "$PROJ_SKILLS/$s"
-            cp "$REPO/$s/SKILL.md" "$PROJ_SKILLS/$s/SKILL.md"
-            cp -R "$REPO/$s/sections" "$PROJ_SKILLS/$s/sections"
-          done
-          mkdir -p "$HOME/.gstack"
-          touch "$HOME/.gstack/.activated" \
-                "$HOME/.gstack/.first-loop-tip-shown" \
-                "$HOME/.gstack/.telemetry-prompted" \
-                "$HOME/.gstack/.proactive-prompted" \
-                "$HOME/.gstack/.completeness-intro-seen" \
-                "$HOME/.gstack/.plan-tune-nudge-shown"
-          touch "$SKILLS_DIR/gstack/.feature-prompted-continuous-checkpoint" \
-                "$SKILLS_DIR/gstack/.feature-prompted-model-overlay"
+        uses: ./.github/actions/register-gstack-skills
 
       - uses: actions/download-artifact@v8
         with:
@@ -277,21 +226,10 @@ jobs:
           persist-credentials: false
 
       - name: Fix bun temp
-        run: |
-          mkdir -p /home/runner/.cache/bun
-          {
-            echo "BUN_INSTALL_CACHE_DIR=/home/runner/.cache/bun"
-            echo "BUN_TMPDIR=/home/runner/.cache/bun"
-            echo "TMPDIR=/home/runner/.cache"
-          } >> "$GITHUB_ENV"
+        uses: ./.github/actions/fix-bun-temp
 
       - name: Restore deps
-        run: |
-          if [ -d /opt/node_modules_cache ] && diff -q /opt/node_modules_cache/.bun.lock bun.lock >/dev/null 2>&1; then
-            cp -r /opt/node_modules_cache node_modules
-          else
-            bun install
-          fi
+        uses: ./.github/actions/restore-deps
 
       - run: bun run build
 

.github/workflows/evals.yml

@@ -524,12 +524,7 @@ jobs:
           persist-credentials: false
 
       - name: Restore deps
-        run: |
-          if [ -d /opt/node_modules_cache ] && diff -q /opt/node_modules_cache/.bun.lock bun.lock >/dev/null 2>&1; then
-            cp -r /opt/node_modules_cache node_modules
-          else
-            bun install
-          fi
+        uses: ./.github/actions/restore-deps
 
       - name: Emit run manifest
         env:
@@ -577,72 +572,26 @@ jobs:
           persist-credentials: false
 
       - name: Fix bun temp
-        run: |
-          mkdir -p /home/runner/.cache/bun
-          {
-            echo "BUN_INSTALL_CACHE_DIR=/home/runner/.cache/bun"
-            echo "BUN_TMPDIR=/home/runner/.cache/bun"
-            echo "TMPDIR=/home/runner/.cache"
-          } >> "$GITHUB_ENV"
+        uses: ./.github/actions/fix-bun-temp
 
       - name: Restore deps
-        run: |
-          if [ -d /opt/node_modules_cache ] && diff -q /opt/node_modules_cache/.bun.lock bun.lock >/dev/null 2>&1; then
-            cp -r /opt/node_modules_cache node_modules
-          else
-            bun install
-          fi
+        uses: ./.github/actions/restore-deps
 
       - run: bun run build
 
       # Any slice can host a PTY smoke, so the seed/registration steps run
       # UNCONDITIONALLY (both are idempotent) — the old matrix keyed them on
-      # matrix.suite.name, which a sliced lane cannot do.
+      # matrix.suite.name, which a sliced lane cannot do. The register
+      # composite carries the fail-fast dangling-symlink/frontmatter
+      # verification loop, so a moved skill target fails HERE in seconds,
+      # not as a wedged PTY session at the shard wall.
       - name: Seed claude interactive config
-        env:
-          ANTHROPIC_API_KEY: ${{ secrets.ANTHROPIC_API_KEY }}
-        run: |
-          node -e '
-            const fs = require("fs"), os = require("os"), path = require("path");
-            const p = path.join(os.homedir(), ".claude.json");
-            const seed = fs.existsSync(p) ? JSON.parse(fs.readFileSync(p, "utf8")) : {};
-            seed.hasCompletedOnboarding = true;
-            const key = process.env.ANTHROPIC_API_KEY || "";
-            if (key) seed.customApiKeyResponses = { approved: [key.slice(-20)], rejected: [] };
-            fs.writeFileSync(p, JSON.stringify(seed, null, 2));
-            console.log("seeded", p);
-          '
+        uses: ./.github/actions/seed-claude-config
+        with:
+          anthropic-api-key: ${{ secrets.ANTHROPIC_API_KEY }}
 
       - name: Register gstack skills for PTY smokes
-        run: |
-          set -eu
-          SKILLS_DIR="$HOME/.claude/skills"
-          REPO="$GITHUB_WORKSPACE"
-          mkdir -p "$SKILLS_DIR"
-          ln -snf "$REPO" "$SKILLS_DIR/gstack"
-          for s in office-hours plan-ceo-review plan-eng-review plan-design-review; do
-            rm -rf "${SKILLS_DIR:?}/$s"
-            mkdir -p "$SKILLS_DIR/$s"
-            cp "$REPO/$s/SKILL.md" "$SKILLS_DIR/$s/SKILL.md"
-            cp -R "$REPO/$s/sections" "$SKILLS_DIR/$s/sections"
-          done
-          PROJ_SKILLS="$REPO/.claude/skills"
-          mkdir -p "$PROJ_SKILLS"
-          for s in office-hours plan-ceo-review plan-eng-review plan-design-review; do
-            rm -rf "${PROJ_SKILLS:?}/$s"
-            mkdir -p "$PROJ_SKILLS/$s"
-            cp "$REPO/$s/SKILL.md" "$PROJ_SKILLS/$s/SKILL.md"
-            cp -R "$REPO/$s/sections" "$PROJ_SKILLS/$s/sections"
-          done
-          mkdir -p "$HOME/.gstack"
-          touch "$HOME/.gstack/.activated" \
-                "$HOME/.gstack/.first-loop-tip-shown" \
-                "$HOME/.gstack/.telemetry-prompted" \
-                "$HOME/.gstack/.proactive-prompted" \
-                "$HOME/.gstack/.completeness-intro-seen" \
-                "$HOME/.gstack/.plan-tune-nudge-shown"
-          touch "$SKILLS_DIR/gstack/.feature-prompted-continuous-checkpoint" \
-                "$SKILLS_DIR/gstack/.feature-prompted-model-overlay"
+        uses: ./.github/actions/register-gstack-skills
 
       - uses: actions/download-artifact@v8
         with: