test(server): run httpapi exercise effect mode in test:httpapi

The test:httpapi script previously ran only coverage and auth modes,
which check route inventory and per-route auth declarations but never
exercise the routes themselves. The exerciser already supports
--mode effect, which dispatches a real request through the new HTTP
API stack for every route in the inventory and verifies a sane
response.

Append the effect mode to test:httpapi so the full route surface gets
exercised before merge. Today's run reports pass=139 fail=0.

Author: kitlangton

packages/opencode/package.json

@@ -9,7 +9,7 @@
     "typecheck": "tsgo --noEmit",
     "test": "bun test --timeout 30000",
     "test:ci": "mkdir -p .artifacts/unit && bun test --timeout 30000 --reporter=junit --reporter-outfile=.artifacts/unit/junit.xml",
-    "test:httpapi": "bun run script/httpapi-exercise.ts --mode coverage --fail-on-missing --fail-on-skip && bun run script/httpapi-exercise.ts --mode auth --fail-on-missing --fail-on-skip",
+    "test:httpapi": "bun run script/httpapi-exercise.ts --mode coverage --fail-on-missing --fail-on-skip && bun run script/httpapi-exercise.ts --mode auth --fail-on-missing --fail-on-skip && bun run script/httpapi-exercise.ts --mode effect --fail-on-missing --fail-on-skip",
     "build": "bun run script/build.ts",
     "fix-node-pty": "bun run script/fix-node-pty.ts",
     "dev": "bun run --conditions=browser ./src/index.ts",