feat: add context optimization features for AI agents (#297)

* feat: add bd prime and setup commands for AI agent integration

This commit consolidates context optimization features for AI agents:

## New Commands

**bd prime** - AI-optimized workflow context injection
- Outputs ~1-2k tokens of workflow context
- Context-aware: adapts to MCP vs CLI mode
- MCP mode: minimal reminders (~500 tokens)
- CLI mode: full command reference (~1-2k tokens)
- Warns against TodoWrite tool and markdown TODOs
- Designed for SessionStart/PreCompact hooks

**bd setup claude** - Claude Code integration installer
- Installs hooks via JSON configuration (not file scripts)
- Supports --project for project-only installation
- Supports --check to verify installation
- Supports --remove to uninstall hooks
- Idempotent (safe to run multiple times)
- Merges with existing settings

**bd setup cursor** - Cursor IDE integration installer
- Creates .cursor/rules/beads.mdc with workflow rules
- Simplified implementation (just overwrites file)

## bd doctor Enhancements

- New: CheckClaude() verifies Claude Code integration
- Detects plugin, MCP server, and hooks installation
- Provides actionable fix suggestions
- Extracted legacy pattern detection to doctor/legacy.go
- Detects JSONL-only mode and warns about legacy issues.jsonl

## Core Improvements

- FindBeadsDir() utility for cross-platform .beads/ discovery
- Works in JSONL-only mode (no database required)
- Sorted noDbCommands alphabetically (one per line for easy diffs)

## Testing

- Unit tests for setup command hook manipulation
- Tests for idempotency, adding/removing hooks
- All tests passing

## Documentation

- cmd/bd/doctor/claude.md - Documents why beads doesn't use Claude Skills
- commands/prime.md - Slash command for bd prime
- Fixed G304 gosec warnings with nosec comments

## Token Efficiency

The bd prime approach reduces AI context usage dramatically:
- MCP mode: ~500 tokens (vs ~10.5k for full MCP tool scan)
- CLI mode: ~1-2k tokens
- 80-99% reduction in standing context overhead

* fix: resolve linting errors in setup utils and remove obsolete test

- Add error check for tmpFile.Close() in setup/utils.go to fix golangci-lint G104
- Remove TestCheckMultipleJSONLFiles test that referenced deleted checkMultipleJSONLFiles function

Fixes golangci-lint errcheck violations introduced in the bd prime/setup feature.

cmd/bd/setup.go

@@ -0,0 +1,78 @@
+package main
+
+import (
+	"github.com/spf13/cobra"
+	"github.com/steveyegge/beads/cmd/bd/setup"
+)
+
+var (
+	setupProject bool
+	setupCheck   bool
+	setupRemove  bool
+)
+
+var setupCmd = &cobra.Command{
+	Use:   "setup",
+	Short: "Setup integration with AI editors",
+	Long:  `Setup integration files for AI editors like Claude Code and Cursor.`,
+}
+
+var setupCursorCmd = &cobra.Command{
+	Use:   "cursor",
+	Short: "Setup Cursor IDE integration",
+	Long: `Install Beads workflow rules for Cursor IDE.
+
+Creates .cursor/rules/beads.mdc with bd workflow context.
+Uses BEGIN/END markers for safe idempotent updates.`,
+	Run: func(cmd *cobra.Command, args []string) {
+		if setupCheck {
+			setup.CheckCursor()
+			return
+		}
+
+		if setupRemove {
+			setup.RemoveCursor()
+			return
+		}
+
+		setup.InstallCursor()
+	},
+}
+
+var setupClaudeCmd = &cobra.Command{
+	Use:   "claude",
+	Short: "Setup Claude Code integration",
+	Long: `Install Claude Code hooks that auto-inject bd workflow context.
+
+By default, installs hooks globally (~/.claude/settings.json).
+Use --project flag to install only for this project.
+
+Hooks call 'bd prime' on SessionStart and PreCompact events to prevent
+agents from forgetting bd workflow after context compaction.`,
+	Run: func(cmd *cobra.Command, args []string) {
+		if setupCheck {
+			setup.CheckClaude()
+			return
+		}
+
+		if setupRemove {
+			setup.RemoveClaude(setupProject)
+			return
+		}
+
+		setup.InstallClaude(setupProject)
+	},
+}
+
+func init() {
+	setupClaudeCmd.Flags().BoolVar(&setupProject, "project", false, "Install for this project only (not globally)")
+	setupClaudeCmd.Flags().BoolVar(&setupCheck, "check", false, "Check if Claude integration is installed")
+	setupClaudeCmd.Flags().BoolVar(&setupRemove, "remove", false, "Remove bd hooks from Claude settings")
+
+	setupCursorCmd.Flags().BoolVar(&setupCheck, "check", false, "Check if Cursor integration is installed")
+	setupCursorCmd.Flags().BoolVar(&setupRemove, "remove", false, "Remove bd rules from Cursor")
+
+	setupCmd.AddCommand(setupClaudeCmd)
+	setupCmd.AddCommand(setupCursorCmd)
+	rootCmd.AddCommand(setupCmd)
+}