feat(import): auto-generate session index after all import paths

Session index (segment/message_context tables) was previously generated
inconsistently: CLI used postImportHook, Desktop relied on a separate
explicit RPC call, and the CLI sync/pull legacy importer never built it.

Move generateSessionIndex / generateIncrementalSessionIndex into the
shared importers (streaming-importer.ts, incremental-importer.ts) so
every caller gets it automatically. Remove the now-redundant calls from
CLI's postImportHook. Also add the calls to the legacy importer.ts used
by CLI sync/pull, which had no session index at all.

Incremental imports use generateIncrementalSessionIndex, which preserves
existing AI summaries. Full imports call generateSessionIndex only on
newly created sessions where no summaries exist.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/cli/src/import/importer.ts

@@ -8,7 +8,14 @@
 import * as fs from 'fs'
 import * as crypto from 'crypto'
 import type { DatabaseAdapter } from '@openchatlab/core'
-import { CHAT_DB_SCHEMA, FTS_TABLE_SCHEMA, generateMessageKey, buildMemberIdMap } from '@openchatlab/core'
+import {
+  CHAT_DB_SCHEMA,
+  FTS_TABLE_SCHEMA,
+  generateMessageKey,
+  buildMemberIdMap,
+  generateSessionIndex,
+  generateIncrementalSessionIndex,
+} from '@openchatlab/core'
 import type { DatabaseManager } from '@openchatlab/node-runtime'
 import { writeParseResultToDb } from '@openchatlab/node-runtime'
 import type { ParsedData, ImportMessage } from './chatlab-reader'
@@ -51,6 +58,12 @@ function fullImport(
 
   buildFts(db, onProgress)
 
+  try {
+    generateSessionIndex(db)
+  } catch {
+    /* non-fatal */
+  }
+
   return { messageCount: stats.messageCount, memberCount: stats.memberCount, duplicateCount: stats.skippedCount }
 }
 
@@ -161,6 +174,11 @@ function incrementalImport(
   if (written > 0) {
     insertFtsEntries(db, onProgress)
     db.prepare('UPDATE meta SET imported_at = ?').run(Math.floor(Date.now() / 1000))
+    try {
+      generateIncrementalSessionIndex(db)
+    } catch {
+      /* non-fatal */
+    }
   }
 
   return { messageCount: written, memberCount: newMembers, duplicateCount: duplicates }

apps/cli/src/import/stream-import.ts

@@ -14,7 +14,6 @@ import {
   analyzeIncrementalImport as sharedAnalyzeIncremental,
   incrementalImport as sharedIncrementalImport,
 } from '@openchatlab/node-runtime'
-import { generateSessionIndex, generateIncrementalSessionIndex } from '@openchatlab/core'
 import type {
   StreamImportResult,
   StreamImportDeps,
@@ -71,13 +70,6 @@ function buildStreamImportDeps(dbManager: DatabaseManager, onProgress?: ImportPr
       dbManager.deleteSessionDatabaseFiles(sessionId)
     },
     onProgress: onProgress ?? (() => {}),
-    postImportHook(db) {
-      try {
-        generateSessionIndex(db)
-      } catch {
-        /* non-fatal: frontend can regenerate via generate-index route */
-      }
-    },
     generateSessionId,
   }
 }
@@ -174,13 +166,6 @@ function buildIncrementalDeps(
       }
     },
     onProgress: onProgress ?? (() => {}),
-    postImportHook(db) {
-      try {
-        generateIncrementalSessionIndex(db)
-      } catch {
-        /* non-fatal */
-      }
-    },
   }
 }