feat: complete OpenCode plugin support with hooks, tools, and commands

Major OpenCode integration overhaul:

- llms.txt: Comprehensive OpenCode documentation for LLMs (642 lines)
- .opencode/plugins/ecc-hooks.ts: All Claude Code hooks translated to OpenCode's plugin system
- .opencode/tools/*.ts: 3 custom tools (run-tests, check-coverage, security-audit)
- .opencode/commands/*.md: All 24 commands in OpenCode format
- .opencode/package.json: npm package structure for opencode-ecc
- .opencode/index.ts: Main plugin entry point

- Delete incorrect LIMITATIONS.md (hooks ARE supported via plugins)
- Rewrite MIGRATION.md with correct hook event mapping
- Update README.md OpenCode section to show full feature parity

OpenCode has 20+ events vs Claude Code's 3 phases:
- PreToolUse → tool.execute.before
- PostToolUse → tool.execute.after
- Stop → session.idle
- SessionStart → session.created
- SessionEnd → session.deleted
- Plus: file.edited, file.watcher.updated, permission.asked, todo.updated

- 12 agents: Full parity
- 24 commands: Full parity (+1 from original 23)
- 16 skills: Full parity
- Hooks: OpenCode has MORE (20+ events vs 3 phases)
- Custom Tools: 3 native OpenCode tools

The OpenCode configuration can now be:
1. Used directly: cd everything-claude-code && opencode
2. Installed via npm: npm install opencode-ecc

.opencode/commands/go-build.md

@@ -0,0 +1,87 @@
+---
+description: Fix Go build and vet errors
+agent: go-build-resolver
+subtask: true
+---
+
+# Go Build Command
+
+Fix Go build, vet, and compilation errors: $ARGUMENTS
+
+## Your Task
+
+1. **Run go build**: `go build ./...`
+2. **Run go vet**: `go vet ./...`
+3. **Fix errors** one by one
+4. **Verify fixes** don't introduce new errors
+
+## Common Go Errors
+
+### Import Errors
+```
+imported and not used: "package"
+```
+**Fix**: Remove unused import or use `_` prefix
+
+### Type Errors
+```
+cannot use x (type T) as type U
+```
+**Fix**: Add type conversion or fix type definition
+
+### Undefined Errors
+```
+undefined: identifier
+```
+**Fix**: Import package, define variable, or fix typo
+
+### Vet Errors
+```
+printf: call has arguments but no formatting directives
+```
+**Fix**: Add format directive or remove arguments
+
+## Fix Order
+
+1. **Import errors** - Fix or remove imports
+2. **Type definitions** - Ensure types exist
+3. **Function signatures** - Match parameters
+4. **Vet warnings** - Address static analysis
+
+## Build Commands
+
+```bash
+# Build all packages
+go build ./...
+
+# Build with race detector
+go build -race ./...
+
+# Build for specific OS/arch
+GOOS=linux GOARCH=amd64 go build ./...
+
+# Run go vet
+go vet ./...
+
+# Run staticcheck
+staticcheck ./...
+
+# Format code
+gofmt -w .
+
+# Tidy dependencies
+go mod tidy
+```
+
+## Verification
+
+After fixes:
+```bash
+go build ./...    # Should succeed
+go vet ./...      # Should have no warnings
+go test ./...     # Tests should pass
+```
+
+---
+
+**IMPORTANT**: Fix errors only. No refactoring, no improvements. Get the build green with minimal changes.