ci(preflight): cache ~/.bun/install/cache keyed on bun.lock

Each of the 5 preflight gates was doing a cold bun install, costing
~30-60s of redundant install time per PR. Cache the install dir
keyed on bun.lock so subsequent preflights (and reruns) hit warm.

Addresses Vai's review on #877.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: jrusso1020

.github/workflows/catalog-previews.yml

@@ -27,6 +27,12 @@ jobs:
       - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
         with:
           node-version: 22
+      - uses: actions/cache@1bd1e32a3bdc45362d1e726936510720a7c30a57 # v4
+        with:
+          path: ~/.bun/install/cache
+          key: bun-${{ runner.os }}-${{ hashFiles('bun.lock') }}
+          restore-keys: |
+            bun-${{ runner.os }}-
       - run: bun install --frozen-lockfile
       - run: bun run lint
       - run: bun run format:check

.github/workflows/player-perf.yml

@@ -49,6 +49,12 @@ jobs:
       - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
         with:
           node-version: 22
+      - uses: actions/cache@1bd1e32a3bdc45362d1e726936510720a7c30a57 # v4
+        with:
+          path: ~/.bun/install/cache
+          key: bun-${{ runner.os }}-${{ hashFiles('bun.lock') }}
+          restore-keys: |
+            bun-${{ runner.os }}-
       - run: bun install --frozen-lockfile
       - run: bun run lint
       - run: bun run format:check

.github/workflows/preview-regression.yml

@@ -53,6 +53,12 @@ jobs:
       - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
         with:
           node-version: 22
+      - uses: actions/cache@1bd1e32a3bdc45362d1e726936510720a7c30a57 # v4
+        with:
+          path: ~/.bun/install/cache
+          key: bun-${{ runner.os }}-${{ hashFiles('bun.lock') }}
+          restore-keys: |
+            bun-${{ runner.os }}-
       - run: bun install --frozen-lockfile
       - run: bun run lint
       - run: bun run format:check

.github/workflows/regression.yml

@@ -46,6 +46,12 @@ jobs:
       - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
         with:
           node-version: 22
+      - uses: actions/cache@1bd1e32a3bdc45362d1e726936510720a7c30a57 # v4
+        with:
+          path: ~/.bun/install/cache
+          key: bun-${{ runner.os }}-${{ hashFiles('bun.lock') }}
+          restore-keys: |
+            bun-${{ runner.os }}-
       - run: bun install --frozen-lockfile
       - run: bun run lint
       - run: bun run format:check

.github/workflows/windows-render.yml

@@ -71,6 +71,12 @@ jobs:
       - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
         with:
           node-version: 22
+      - uses: actions/cache@1bd1e32a3bdc45362d1e726936510720a7c30a57 # v4
+        with:
+          path: ~/.bun/install/cache
+          key: bun-${{ runner.os }}-${{ hashFiles('bun.lock') }}
+          restore-keys: |
+            bun-${{ runner.os }}-
       - run: bun install --frozen-lockfile
       - run: bun run lint
       - run: bun run format:check