feat: add plan file context injection with toggle (#180)

[ThanhNguyxn]

Summary

Implements feature request from #180 - adds the ability to include the most recent plan file from ~/.claude/plans/ in the context injection.

Changes

Backend - Settings Infrastructure

• SettingsDefaultsManager.ts: Added CLAUDE_MEM_CONTEXT_SHOW_LAST_PLAN setting (default: false)

Backend - Context Generator

• context-generator.ts:
  • Added getMostRecentPlanFile() helper function to read the latest .md file from ~/.claude/plans/
  • Extracts plan title from H1 heading
  • Injects plan content into context output when toggle is enabled

Backend - Settings API

• SettingsRoutes.ts: Added the new setting key to allowed settings list and boolean validation

Frontend - UI Types

• types.ts: Added CLAUDE_MEM_CONTEXT_SHOW_LAST_PLAN to Settings interface

How It Works

1. User enables CLAUDE_MEM_CONTEXT_SHOW_LAST_PLAN in settings (via ~/.claude-mem/settings.json or future UI toggle)
2. On SessionStart, context-generator reads ~/.claude/plans/ directory
3. Most recent .md file (by modification time) is selected
4. Plan title is extracted from the first H1 heading
5. Full plan content is injected into context with header showing title and file path

Example Output

---

**📋 Last Plan: Fix Authentication Flow**
_File: /home/user/.claude/plans/federated-wandering-volcano.md_

# Fix Authentication Flow

## Steps
1. Update token validation...

Testing

• ✅ Follows existing settings pattern
• ✅ Graceful handling when no plans exist
• ✅ Error logging for file read failures

Closes #180

[Copilot]

Pull request overview

This PR adds the ability to inject the most recent plan file from ~/.claude/plans/ into the context when enabled via a new setting CLAUDE_MEM_CONTEXT_SHOW_LAST_PLAN. The implementation follows the existing pattern used for CLAUDE_MEM_CONTEXT_SHOW_LAST_SUMMARY and CLAUDE_MEM_CONTEXT_SHOW_LAST_MESSAGE.

Key Changes

• Added new toggle setting CLAUDE_MEM_CONTEXT_SHOW_LAST_PLAN (defaults to false)
• Implemented plan file discovery and content injection in context generator
• Extracts plan title from H1 heading for display

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

File	Description
src/ui/viewer/types.ts	Added CLAUDE_MEM_CONTEXT_SHOW_LAST_PLAN property to Settings interface
src/shared/SettingsDefaultsManager.ts	Added default value for new setting (false) in SettingsDefaults interface and DEFAULTS object
src/services/worker/http/routes/SettingsRoutes.ts	Added new setting to allowed keys list and boolean validation
src/services/context-generator.ts	Implemented getMostRecentPlanFile() helper function and integrated plan content injection into context output, plus minor indentation formatting improvements

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[Copilot]

The statSync call is being made twice for each file - once in the map function to get the full path and again to retrieve mtime. This can be optimized by first constructing the full path, then calling statSync once per file. Consider restructuring to avoid the redundant filesystem calls.

Suggested change

	.map((f: string) => ({
	name: f,
	path: path.join(plansDir, f),
	mtime: statSync(path.join(plansDir, f)).mtime.getTime()
	}))
	.map((f: string) => {
	const fullPath = path.join(plansDir, f);
	const stat = statSync(fullPath);
	return {
	name: f,
	path: fullPath,
	mtime: stat.mtime.getTime()
	};
	})

[Copilot]

The regex pattern /^#\s+(.+)$/m will match the first H1 heading anywhere in the file, but it could match a heading with trailing whitespace. Consider trimming the captured title with .trim() to ensure clean titles, like: const title = titleMatch?.[1]?.trim() || mostRecent.name.replace('.md', '');

Suggested change

	const title = titleMatch?.[1] || mostRecent.name.replace('.md', '');
	const title = titleMatch?.[1]?.trim() || mostRecent.name.replace('.md', '');