[Bug] Memory workflow only writes to sessions/<id>/ scratch path and never promotes to long-term data/memory/projects/ #415

Describe the bug
The Memory Workflow generates a file like /Users/<user>/.openloomi/sessions/<session-id>/TN-Alpha-memory.md. To make it retrievable across sessions, the user has to manually copy that file into the long-term memory directory. Workflow success does not equal memory saved.

To Reproduce

1. Ask OpenLoomi to remember project TN-Alpha.
2. Run the memory workflow (or the memorize skill).
3. Inspect the long-term project memory directory: data/memory/projects/ is empty.
4. The file lives only under sessions/<id>/ and is invisible to future sessions.
5. Restart / start a new session; the project memory is not retrieved.

Expected behavior
The workflow's "save" step should atomically promote its output to data/memory/projects/<slug>.md — the canonical long-term directory defined by apps/web/lib/ai/memory/fs-sync.ts:30. The slug is derived from the project name (stable, lowercase, ASCII-safe). Promotion should be part of the workflow's contract, not a separate manual action.

Screenshots
N/A

Desktop

• OS: any
• App: OpenLoomi desktop (Tauri) and web

Additional context

• getMemoryFsPath() already returns the canonical long-term path; only the workflow's writer path is wrong.
• Related: apps/web/lib/ai/memory/chat-sync.ts and the session-scoped helpers in the same folder need to be unified into one save flow that distinguishes "session draft" from "long-term memory".