refactor(background): implement event-driven fire-and-forget tasks (alvinunreal#89)

* refactor(background): implement event-driven fire-and-forget tasks

- BackgroundTaskManager now launches tasks in ~1ms (fire-and-forget)
- Uses session.status events instead of deprecated session.idle
- Adds start queue with configurable concurrency limit (default: 10)
- Optional notification to parent session on completion
- Removes sync mode and legacy polling-based approach
- Simplified tool API: background_task, background_output, background_cancel

BREAKING CHANGE: Removed sync/async mode, session.create, sendPrompt,
pollSession, resolveSessionId, extractResponseText exports

* fix(PR#89): address review comments

- TmuxSessionManager: call startPolling() for fallback reliability
- Remove redundant assignments before completeTask() in cancel()
- Remove unused model parameter from LaunchOptions
- Remove unused POLL_INTERVAL_BACKGROUND_MS import
- Remove unused createSessionCreatedHandler/createSessionStatusHandler methods
- Fix misplaced comment in schema.ts

* fix(PR#89): add cancelled status checks

- completeTask: guard now checks cancelled status
- background.ts: waitForCompletion skips cancelled tasks

* fix(PR#89): address remaining review comments
- Fix activeStarts leak in startTask early return
- Add resolver cleanup to prevent memory leak
- Fix race condition in cancel() by marking cancelled first

* Update src/background/background-manager.ts

Co-authored-by: greptile-apps[bot] <165735046+greptile-apps[bot]@users.noreply.github.com>

---------

Co-authored-by: “nghyane” <“hoangvananhnghia99@gmail.com”>
Co-authored-by: Alvin <alvin@cmngoal.com>
Co-authored-by: greptile-apps[bot] <165735046+greptile-apps[bot]@users.noreply.github.com>

Author: 4 people

AGENTS.md

@@ -0,0 +1,95 @@
+# Agent Coding Guidelines
+
+This document provides guidelines for AI agents operating in this repository.
+
+## Project Overview
+
+**oh-my-opencode-slim** - A lightweight agent orchestration plugin for OpenCode, a slimmed-down fork of oh-my-opencode. Built with TypeScript, Bun, and Biome.
+
+## Commands
+
+| Command | Description |
+|---------|-------------|
+| `bun run build` | Build TypeScript to `dist/` (both index.ts and cli/index.ts) |
+| `bun run typecheck` | Run TypeScript type checking without emitting |
+| `bun test` | Run all tests with Bun |
+| `bun run lint` | Run Biome linter on entire codebase |
+| `bun run format` | Format entire codebase with Biome |
+| `bun run check` | Run Biome check with auto-fix (lint + format + organize imports) |
+| `bun run check:ci` | Run Biome check without auto-fix (CI mode) |
+| `bun run dev` | Build and run with OpenCode |
+
+**Running a single test:** Use Bun's test filtering with the `-t` flag:
+```bash
+bun test -t "test-name-pattern"
+```
+
+## Code Style
+
+### General Rules
+- **Formatter/Linter:** Biome (configured in `biome.json`)
+- **Line width:** 80 characters
+- **Indentation:** 2 spaces
+- **Line endings:** LF (Unix)
+- **Quotes:** Single quotes in JavaScript/TypeScript
+- **Trailing commas:** Always enabled
+
+### TypeScript Guidelines
+- **Strict mode:** Enabled in `tsconfig.json`
+- **No explicit `any`:** Generates a linter warning (disabled for test files)
+- **Module resolution:** `bundler` strategy
+- **Declarations:** Generate `.d.ts` files in `dist/`
+
+### Imports
+- Biome auto-organizes imports on save (`organizeImports: "on"`)
+- Let the formatter handle import sorting
+- Use path aliases defined in TypeScript configuration if present
+
+### Naming Conventions
+- **Variables/functions:** camelCase
+- **Classes/interfaces:** PascalCase
+- **Constants:** SCREAMING_SNAKE_CASE
+- **Files:** kebab-case for most, PascalCase for React components
+
+### Error Handling
+- Use typed errors with descriptive messages
+- Let errors propagate appropriately rather than catching silently
+- Use Zod for runtime validation (already a dependency)
+
+### Git Integration
+- Biome integrates with git (VCS enabled)
+- Commits should pass `bun run check:ci` before pushing
+
+## Project Structure
+
+```
+oh-my-opencode-slim/
+├── src/              # TypeScript source files
+├── dist/             # Built JavaScript and declarations
+├── node_modules/     # Dependencies
+├── biome.json        # Biome configuration
+├── tsconfig.json     # TypeScript configuration
+└── package.json      # Project manifest and scripts
+```
+
+## Key Dependencies
+
+- `@modelcontextprotocol/sdk` - MCP protocol implementation
+- `@opencode-ai/sdk` - OpenCode AI SDK
+- `zod` - Runtime validation
+- `vscode-jsonrpc` / `vscode-languageserver-protocol` - LSP support
+
+## Development Workflow
+
+1. Make code changes
+2. Run `bun run check:ci` to verify linting and formatting
+3. Run `bun run typecheck` to verify types
+4. Run `bun test` to verify tests pass
+5. Commit changes
+
+## Common Patterns
+
+- This is an OpenCode plugin - most functionality lives in `src/`
+- The CLI entry point is `src/cli/index.ts`
+- The main plugin export is `src/index.ts`
+- Skills are located in `src/skills/` (included in package publish)