fix: replace bunx with bun run for packages in lock file

Replace bunx usage with bun run for all packages listed in
devDependencies to ensure deterministic builds and consistent
versions across environments.

Changes:
- Update package.json scripts to use local binaries instead of bunx
  - lint: ultracite fix (now uses v6.4.2 from devDependencies)
  - lint:check: ultracite check
  - install:chromium: playwright install chromium
- Update PostToolUse hook to run bun run lint && bun run type:check
- Add documentation clarifying when to use bunx vs bun run
- Update E2E test commands in docs to prefer bun run scripts

Why this matters:
bunx uses Bun's global cache and may ignore lock file versions,
leading to inconsistent behavior. Using bun run ensures all
developers and CI use the exact versions specified in bun.lockb.

References:
- oven-sh/bun#4183
- oven-sh/bun#12245

Co-Authored-By: Claude Sonnet 4.5 (1M context) <noreply@anthropic.com>

Author: sago2k8

frontend/.claude/settings.json

@@ -6,7 +6,7 @@
         "hooks": [
           {
             "type": "command",
-            "command": "bun x ultracite fix"
+            "command": "bun run lint && bun run type:check"
           }
         ]
       }

frontend/package.json

@@ -14,7 +14,7 @@
     "preview": "rsbuild preview",
     "build": "NODE_OPTIONS=--max_old_space_size=16384 rsbuild build",
     "build-local-test": "REACT_APP_BUSINESS=true REACT_APP_CONSOLE_GIT_SHA=abc123 REACT_APP_CONSOLE_GIT_REF=local REACT_APP_BUILD_TIMESTAMP=32503680000 REACT_APP_DEV_HINT=true NODE_OPTIONS=--max_old_space_size=16384 rsbuild build",
-    "install:chromium": "bunx playwright install chromium",
+    "install:chromium": "playwright install chromium",
     "e2e-test": "node tests/scripts/run-all-variants.mjs",
     "e2e-test:variant": "node tests/scripts/run-variant.mjs",
     "e2e-test:dev": "E2E_DEV_MODE=true node tests/scripts/run-variant.mjs console --ui",
@@ -30,10 +30,10 @@
     "test:file:integration": "NODE_OPTIONS='--max_old_space_size=4096 --loader=./tests/css-loader.mjs' TZ=GMT vitest run --config=vitest.config.integration.mts",
     "type:check": "tsgo --noEmit --incremental --p tsconfig.base.json",
     "type:check:file": "tsgo --noEmit -p tsconfig.base.json",
-    "lint": "bun x ultracite fix",
-    "lint:check": "bun x ultracite check",
-    "lint:file": "bun x ultracite fix",
-    "lint:check:file": "bun x ultracite check",
+    "lint": "ultracite fix",
+    "lint:check": "ultracite check",
+    "lint:file": "ultracite fix",
+    "lint:check:file": "ultracite check",
     "format:check": "biome format src/*",
     "format": "biome format src/* --write",
     "load-git-hooks": "cd .. && git config core.hooksPath \"./.git-hooks\"",