refactor: retire legacy src/ hooks; migrate all live behavior to the daemon path

[nickroci]

What & why

Two hook systems ran in parallel: the legacy src/ hooks (package "agent-mem") and the current plugin/daemon path (ultan/ + hooks/hooks.json). The switch to the plugin silently dropped several behaviors that were live before it. This removes src/ entirely and ports every behavior that was live before the switch (the 7-hook ~/.claude/settings.json.ultan-bak set) into the daemon path.

Migrated (were live, lost at the switch)

• Assistant-prose capture — the daemon now reads the Claude Code transcript on a sealing Stop/SessionEnd and folds the assistant's natural-language turns into the buffer the Librarian sees. Before, only user prompts + tool I/O were captured, so design reasoning never reached memory. daemon/agent_mem_daemon/transcript.py + scheduler injection; ultan/_hooks.py forwards transcript_path.
• PreToolUse tool-blocking — re-added the dropped 7th hook + ultan/_blockers.py (block_triggers, severity deny|advise). Was live until 2026-06-09 (18k PreToolUse events).
• Nudge consume/budget/inject — ultan/_nudges.py completes a half-migrated pipeline: the Scholar still wrote pending-nudges.md but nothing consumed it.
• SessionStart boot-context injection — ultan/_session_context.py (the old handler returned 0 without emitting the additionalContext envelope).
• project_slug priming parity.

Removed

• The entire src/ tree + its workspace member, set-version.sh / check-version-coherence.sh entries, CI matrix entry, a dead agent-mem dep.
• /ultan-install (install.py + README + global command file) — the plugin owns hook installation now.

Preserved / rebuilt

• agent-mem doctor's structural lint reimplemented in-process (tools/search/_lint.py); it had shelled out to the deleted src/scripts/lint.py. Resolution mirrors the daemon's wikilink_resolves, so it's accurate (0 false broken-links / orphans on the real 542-entry library).

Reviewer notes (judgment calls)

• Thin-install safety: ultan/ imports no aliases (retrieval-only) — bucket helpers are mirrored locally, matching _priming.py / _session_context.py, so the base install + the no-extra CI job pass. (A regression here was caught and fixed mid-work.)
• Dropped the lint missing_backlink check: it produced 555 noise suggestions (this library links content one-directionally by design). Trivial to restore if you want strict parity.
• Assistant-prose is best-effort: a per-session marker dedups; failures degrade to no-prose and never break ingestion.

Verification

• 79 ultan · 683 daemon (90.6% cov) · 171 tools/search · pyright 0 · ruff + format clean · version coherence OK.
• agent-mem doctor runs clean against the real store.

🤖 Generated with Claude Code