fix(ui-parser): restore esbuild CJS bundle step lost in PR #11 merge

Commit 0e43811 added an esbuild step to bundle src/ui-parser.ts as CJS
because the UI's sandboxed worker can't evaluate ESM `export` syntax.
PR #11 (filesystem-log-tail) was based on a commit predating that fix,
so the merge clobbered both the build:ui-parser script and the esbuild
devDependency. Every release since has shipped a tsc-emitted ESM
ui-parser.js that the worker silently fails to load — parseStdoutLine
never registers and the run transcript falls back to dumping raw
stream-json lines as plain text instead of rendering structured
assistant/thinking/tool_call/tool_result entries.

Restore the script and dep verbatim from 0e43811.

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

package.json

@@ -25,7 +25,8 @@
     "dist"
   ],
   "scripts": {
-    "build": "tsc",
+    "build": "tsc && npm run build:ui-parser",
+    "build:ui-parser": "esbuild src/ui-parser.ts --bundle --format=cjs --target=es2020 --outfile=dist/ui-parser.js --log-level=warning",
     "clean": "rm -rf dist",
     "typecheck": "tsc --noEmit",
     "test": "vitest run",
@@ -43,6 +44,7 @@
     "@paperclipai/adapter-utils": "2026.415.0-canary.7",
     "@types/node": "^24.6.0",
     "@vitest/coverage-v8": "^4.1.4",
+    "esbuild": "^0.24.0",
     "typescript": "^5.7.3",
     "vitest": "^4.1.4"
   }