feat: Implement Phase 1 of SDK agent architecture with hook integration

- Added CLI commands for context, new session, save observation, and summary.
- Created HooksDatabase for managing SDK sessions and observations.
- Implemented migration 004 to add new tables: sdk_sessions, observation_queue, observations, and session_summaries.
- Developed hook functions for context display, session initialization, observation queuing, and session finalization.
- Added comprehensive tests for database schema and hook functionality.
- Documented Phase 1 implementation in PHASE1-COMPLETE.md.

src/hooks/context.ts

@@ -0,0 +1,92 @@
+import { HooksDatabase } from '../services/sqlite/HooksDatabase.js';
+import { PathDiscovery } from '../services/path-discovery.js';
+import path from 'path';
+
+export interface SessionStartInput {
+  session_id: string;
+  cwd: string;
+  source?: string;
+  [key: string]: any;
+}
+
+/**
+ * Context Hook - SessionStart
+ * Shows user what happened in recent sessions
+ */
+export function contextHook(input: SessionStartInput): void {
+  try {
+    // Only run on startup (not on resume)
+    if (input.source && input.source !== 'startup') {
+      console.log(''); // Output nothing, just exit
+      process.exit(0);
+    }
+
+    // Extract project from cwd
+    const project = path.basename(input.cwd);
+
+    // Get recent summaries
+    const db = new HooksDatabase();
+    const summaries = db.getRecentSummaries(project, 5);
+    db.close();
+
+    // If no summaries, exit silently
+    if (summaries.length === 0) {
+      console.log(''); // Output nothing
+      process.exit(0);
+    }
+
+    // Format output for Claude
+    const output: string[] = [];
+    output.push('# Recent Session Context');
+    output.push('');
+    output.push(`Here's what happened in recent ${project} sessions:`);
+    output.push('');
+
+    for (const summary of summaries) {
+      output.push('---');
+      output.push('');
+
+      if (summary.request) {
+        output.push(`**Request:** ${summary.request}`);
+      }
+
+      if (summary.completed) {
+        output.push(`**Completed:** ${summary.completed}`);
+      }
+
+      if (summary.learned) {
+        output.push(`**Learned:** ${summary.learned}`);
+      }
+
+      if (summary.next_steps) {
+        output.push(`**Next Steps:** ${summary.next_steps}`);
+      }
+
+      if (summary.files_edited) {
+        try {
+          const files = JSON.parse(summary.files_edited);
+          if (Array.isArray(files) && files.length > 0) {
+            output.push(`**Files Edited:** ${files.join(', ')}`);
+          }
+        } catch {
+          // If not valid JSON, show as text
+          if (summary.files_edited.trim()) {
+            output.push(`**Files Edited:** ${summary.files_edited}`);
+          }
+        }
+      }
+
+      output.push(`**Date:** ${summary.created_at.split('T')[0]}`);
+      output.push('');
+    }
+
+    // Output to stdout for Claude Code to inject
+    console.log(output.join('\n'));
+    process.exit(0);
+
+  } catch (error: any) {
+    // On error, exit silently - don't block Claude Code
+    console.error(`[claude-mem context error: ${error.message}]`);
+    process.exit(0);
+  }
+}