fix(memory): /memory on fails silently for uninitialized projects — should tell the user to run /init

[LeXwDeX]

Repro

A project that never ran /init (project.time_initialized NULL) answers /memory on with a silent "Memory remains off". Real case: a project created 2026-08-18 with real git identity (remote + commits) — the only missing gate is the /init stamp. Global memory/projects/ had zero homes because of this.

Expected

/memory on (and memory_search) should surface the reason: "project not initialized — run /init first" instead of failing closed with a generic off-state message. The /init requirement itself is by design (fail-closed until time_initialized); only the messaging is missing.

Acceptance

• /memory on in an uninitialized project prints an actionable hint
• memory_search same

[LeXwDeX]

Delivered via PR #365 (merged to dev). statusReason() names the gate (missing /init stamp, global identity, non-git); setEnabled(true) and memory_search carry it. The repro project (git identity, no /init) now gets 'run /init first, then /memory on'. specgit finish exit 0.