feat(memory): add sqlite_journal_mode config for shared filesystem support

SQLite WAL mode requires shared-memory (mmap/shm) which is unavailable
on many network and virtual shared filesystems (NFS, SMB/CIFS,
UTM/VirtioFS, VirtualBox shared folders), causing xShmMap I/O errors
at startup.

Add `sqlite_journal_mode` config option under `[memory]` that accepts
"wal" (default) or "delete". When set to "delete", SQLite uses the
legacy DELETE journal mode and disables mmap, allowing ZeroClaw to run
with workspaces on shared/network filesystems.

Usage:
  [memory]
  sqlite_journal_mode = "delete"

Changes:
- config/schema.rs: Add sqlite_journal_mode field to MemoryConfig
- memory/sqlite.rs: Add with_options() supporting journal mode selection
- memory/mod.rs: Pass journal_mode from config to SqliteMemory
- onboard/wizard.rs: Include new field in default MemoryConfig

src/memory/mod.rs

@@ -262,13 +262,14 @@ pub fn create_memory_with_storage_and_routes(
             ));
 
         #[allow(clippy::cast_possible_truncation)]
-        let mem = SqliteMemory::with_embedder(
+        let mem = SqliteMemory::with_options(
             workspace_dir,
             embedder,
             config.vector_weight as f32,
             config.keyword_weight as f32,
             config.embedding_cache_size,
             config.sqlite_open_timeout_secs,
+            &config.sqlite_journal_mode,
         )?;
         Ok(mem)
     }