Fix: Add sandbox-awareness recovery nudge after repeated tool denials (#5)

When the agent repeatedly hits permission denials or tool errors, it now
receives a nudge after 2 consecutive failures to guide it toward finding
an alternative approach within the allowed workspace.

Changes:
- Track permission denials via permission.replied event
- Track tool errors via tool.execute.after hook (permission-related errors)
- Reset deny counter when session status transitions to busy
- Configurable threshold via OPENCODE_DENY_THRESHOLD env var (default: 2)
- Added unit tests covering all acceptance criteria
- Import getOrCreateState from throttle.ts (avoid duplication)

Fixes #5

Author: OpenCode Runner

issue-5-comment-4165628200-results.txt

@@ -0,0 +1 @@
+Now I understand the codebase. Let me implement the sandbox-awareness feature.

opencode-nudge/package-lock.json

@@ -36,6 +36,7 @@
     "@opencode-ai/sdk": "^1.3.6",
     "@tsconfig/node22": "^22.0.0",
     "@types/node": "^22.0.0",
+    "bun": "^1.3.11",
     "bun-types": "^1.3.11",
     "typescript": "^5.8.2"
   }