feat: make extension system packageable via enriched ExtensionContext

Enrich ExtensionContext with supabase, emit(), settings, storage, log,
and services so extensions can receive everything through dependency
injection instead of importing core modules directly.

- Add context factory and inject context into event handlers via registry
- Move supplier invoice journal entry creation to core event handler
- Add services.ingestTransactions to ExtensionContext for enable-banking
- Create catch-all API route for extension-declared apiRoutes
- Migrate 5 extensions to accept context with dynamic import fallbacks

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

extensions/general/ai-categorization/index.ts

@@ -1,5 +1,4 @@
-import { createClient } from '@/lib/supabase/server'
-import type { Extension } from '@/lib/extensions/types'
+import type { Extension, ExtensionContext } from '@/lib/extensions/types'
 import type { EventPayload } from '@/lib/events/types'
 import type { Transaction, EntityType } from '@/types'
 import {
@@ -26,7 +25,15 @@ const DEFAULT_SETTINGS: AiCategorizationSettings = {
   providerModel: 'claude-haiku-4-5-20251001',
 }
 
+/** Get settings via ExtensionContext (preferred in event handlers) */
+async function getSettingsViaCtx(ctx: ExtensionContext): Promise<AiCategorizationSettings> {
+  const stored = await ctx.settings.get<Partial<AiCategorizationSettings>>()
+  return { ...DEFAULT_SETTINGS, ...(stored || {}) }
+}
+
+/** Get settings for external callers (settings routes, on-demand API) */
 export async function getSettings(userId: string): Promise<AiCategorizationSettings> {
+  const { createClient } = await import('@/lib/supabase/server')
   const supabase = await createClient()
 
   const { data } = await supabase
@@ -38,7 +45,6 @@ export async function getSettings(userId: string): Promise<AiCategorizationSetti
     .single()
 
   if (!data?.value) return { ...DEFAULT_SETTINGS }
-
   return { ...DEFAULT_SETTINGS, ...(data.value as Partial<AiCategorizationSettings>) }
 }
 
@@ -49,6 +55,7 @@ export async function saveSettings(
   const current = await getSettings(userId)
   const merged = { ...current, ...partial }
 
+  const { createClient } = await import('@/lib/supabase/server')
   const supabase = await createClient()
 
   await supabase
@@ -87,6 +94,7 @@ export async function categorizeTransactions(
   userId: string,
   transactionIds: string[]
 ): Promise<CategorizationSuggestion[]> {
+  const { createClient } = await import('@/lib/supabase/server')
   const supabase = await createClient()
   const settings = await getSettings(userId)
 
@@ -125,12 +133,14 @@ export async function categorizeTransactions(
 // ============================================================
 
 async function handleTransactionSynced(
-  payload: EventPayload<'transaction.synced'>
+  payload: EventPayload<'transaction.synced'>,
+  ctx?: ExtensionContext
 ): Promise<void> {
   const { transactions: syncedTransactions, userId } = payload
+  const log = ctx?.log ?? console
 
   // Gate: Is autoSuggestEnabled?
-  const settings = await getSettings(userId)
+  const settings = ctx ? await getSettingsViaCtx(ctx) : await getSettings(userId)
   if (!settings.autoSuggestEnabled) {
     return
   }
@@ -143,12 +153,10 @@ async function handleTransactionSynced(
     return
   }
 
-  console.log(
-    `[ai-categorization] Auto-suggest triggered for ${uncategorized.length} uncategorized transactions`
-  )
+  log.info(`Auto-suggest triggered for ${uncategorized.length} uncategorized transactions`)
 
   try {
-    const supabase = await createClient()
+    const supabase = ctx?.supabase ?? await (await import('@/lib/supabase/server')).createClient()
 
     const batch: TransactionForCategorization[] = uncategorized.map((t: Transaction) => ({
       id: t.id,
@@ -173,11 +181,11 @@ async function handleTransactionSynced(
       await storeSuggestions(userId, qualifiedSuggestions, supabase)
     }
 
-    console.log(
-      `[ai-categorization] Generated ${suggestions.length} suggestions, ${qualifiedSuggestions.length} above threshold (${settings.confidenceThreshold})`
+    log.info(
+      `Generated ${suggestions.length} suggestions, ${qualifiedSuggestions.length} above threshold (${settings.confidenceThreshold})`
     )
   } catch (error) {
-    console.error('[ai-categorization] handleTransactionSynced failed:', error)
+    log.error('handleTransactionSynced failed:', error)
   }
 }
 
@@ -251,6 +259,6 @@ export const aiCategorizationExtension: Extension = {
     path: '/settings/extensions/ai-categorization',
   },
   async onInstall(ctx) {
-    await saveSettings(ctx.userId, DEFAULT_SETTINGS)
+    await ctx.settings.set('settings', DEFAULT_SETTINGS)
   },
 }