feat: isolate Claude and Codex session sources

Persist platform_source across session creation, transcript ingestion, API query paths, and viewer state so Claude and Codex data can coexist without bleeding into each other.

- add platform-source normalization helpers and persist platform_source in sdk_sessions via migration 24 with backfill and indexing
- thread platformSource through CLI hooks, transcript processing, context generation, pagination, search routes, SSE payloads, and session management
- expose source-aware project catalogs, viewer tabs, context preview selectors, and source badges for observations, prompts, and summaries
- start the transcript watcher from the worker for transcript-based clients and preserve platform source during Codex ingestion
- auto-start the worker from the MCP server for MCP-only clients and tighten stdio-driven cleanup during shutdown
- keep createSDKSession backward compatible with existing custom-title callers while allowing explicit platform source forwarding

src/services/worker/PaginationHelper.ts

@@ -71,14 +71,54 @@ export class PaginationHelper {
   /**
    * Get paginated observations
    */
-  getObservations(offset: number, limit: number, project?: string): PaginatedResult<Observation> {
-    const result = this.paginate<Observation>(
-      'observations',
-      'id, memory_session_id, project, type, title, subtitle, narrative, text, facts, concepts, files_read, files_modified, prompt_number, created_at, created_at_epoch',
+  getObservations(offset: number, limit: number, project?: string, platformSource?: string): PaginatedResult<Observation> {
+    const db = this.dbManager.getSessionStore().db;
+    let query = `
+      SELECT
+        o.id,
+        o.memory_session_id,
+        o.project,
+        COALESCE(s.platform_source, 'claude') as platform_source,
+        o.type,
+        o.title,
+        o.subtitle,
+        o.narrative,
+        o.text,
+        o.facts,
+        o.concepts,
+        o.files_read,
+        o.files_modified,
+        o.prompt_number,
+        o.created_at,
+        o.created_at_epoch
+      FROM observations o
+      LEFT JOIN sdk_sessions s ON o.memory_session_id = s.memory_session_id
+    `;
+    const params: unknown[] = [];
+    const conditions: string[] = [];
+
+    if (project) {
+      conditions.push('o.project = ?');
+      params.push(project);
+    }
+    if (platformSource) {
+      conditions.push(`COALESCE(s.platform_source, 'claude') = ?`);
+      params.push(platformSource);
+    }
+    if (conditions.length > 0) {
+      query += ` WHERE ${conditions.join(' AND ')}`;
+    }
+
+    query += ' ORDER BY o.created_at_epoch DESC LIMIT ? OFFSET ?';
+    params.push(limit + 1, offset);
+
+    const results = db.prepare(query).all(...params) as Observation[];
+    const result: PaginatedResult<Observation> = {
+      items: results.slice(0, limit),
+      hasMore: results.length > limit,
       offset,
-      limit,
-      project
-    );
+      limit
+    };
 
     // Strip project paths from file paths before returning
     return {
@@ -90,13 +130,14 @@ export class PaginationHelper {
   /**
    * Get paginated summaries
    */
-  getSummaries(offset: number, limit: number, project?: string): PaginatedResult<Summary> {
+  getSummaries(offset: number, limit: number, project?: string, platformSource?: string): PaginatedResult<Summary> {
     const db = this.dbManager.getSessionStore().db;
 
     let query = `
       SELECT
         ss.id,
         s.content_session_id as session_id,
+        COALESCE(s.platform_source, 'claude') as platform_source,
         ss.request,
         ss.investigated,
         ss.learned,
@@ -110,11 +151,22 @@ export class PaginationHelper {
     `;
     const params: any[] = [];
 
+    const conditions: string[] = [];
+
     if (project) {
-      query += ' WHERE ss.project = ?';
+      conditions.push('ss.project = ?');
       params.push(project);
     }
 
+    if (platformSource) {
+      conditions.push(`COALESCE(s.platform_source, 'claude') = ?`);
+      params.push(platformSource);
+    }
+
+    if (conditions.length > 0) {
+      query += ` WHERE ${conditions.join(' AND ')}`;
+    }
+
     query += ' ORDER BY ss.created_at_epoch DESC LIMIT ? OFFSET ?';
     params.push(limit + 1, offset);
 
@@ -132,21 +184,40 @@ export class PaginationHelper {
   /**
    * Get paginated user prompts
    */
-  getPrompts(offset: number, limit: number, project?: string): PaginatedResult<UserPrompt> {
+  getPrompts(offset: number, limit: number, project?: string, platformSource?: string): PaginatedResult<UserPrompt> {
     const db = this.dbManager.getSessionStore().db;
 
     let query = `
-      SELECT up.id, up.content_session_id, s.project, up.prompt_number, up.prompt_text, up.created_at, up.created_at_epoch
+      SELECT
+        up.id,
+        up.content_session_id,
+        s.project,
+        COALESCE(s.platform_source, 'claude') as platform_source,
+        up.prompt_number,
+        up.prompt_text,
+        up.created_at,
+        up.created_at_epoch
       FROM user_prompts up
       JOIN sdk_sessions s ON up.content_session_id = s.content_session_id
     `;
     const params: any[] = [];
 
+    const conditions: string[] = [];
+
     if (project) {
-      query += ' WHERE s.project = ?';
+      conditions.push('s.project = ?');
       params.push(project);
     }
 
+    if (platformSource) {
+      conditions.push(`COALESCE(s.platform_source, 'claude') = ?`);
+      params.push(platformSource);
+    }
+
+    if (conditions.length > 0) {
+      query += ` WHERE ${conditions.join(' AND ')}`;
+    }
+
     query += ' ORDER BY up.created_at_epoch DESC LIMIT ? OFFSET ?';
     params.push(limit + 1, offset);