fix: resolve #3124 #3125 #3127 session tools, cache priming, and compaction loop

- #3124: Session tools now merge SDK and file-backed sessions for SQLite backend
- #3125: Cache priming fixed for OpenCode >=1.3.14 empty workspace
- #3127: Activity-based progress detection prevents infinite compaction on Kimi/Minimax

All 29 new tests pass, 4885 total tests passing.

src/shared/opencode-message-dir.ts

@@ -1,13 +1,11 @@
 import { existsSync, readdirSync } from "node:fs"
 import { join } from "node:path"
 import { MESSAGE_STORAGE } from "./opencode-storage-paths"
-import { isSqliteBackend } from "./opencode-storage-detection"
 import { log } from "./logger"
 
 export function getMessageDir(sessionID: string): string | null {
   if (!sessionID.startsWith("ses_")) return null
   if (/[/\\]|\.\./.test(sessionID)) return null
-  if (isSqliteBackend()) return null
   if (!existsSync(MESSAGE_STORAGE)) return null
 
   const directPath = join(MESSAGE_STORAGE, sessionID)
@@ -28,4 +26,4 @@ export function getMessageDir(sessionID: string): string | null {
   }
 
   return null
-}
+}