Replace the ``pov_summary`` column in ``search_all_memories``'s SELECT
with ``snippet(memories_fts, 0, '<mark>', '</mark>', '…', 32)`` so each
match in a result row is wrapped in ``<mark>`` for the search-results
UI. The original ``pov_summary`` is still returned alongside as a
non-highlighted fallback. Template renders ``r.snippet|safe`` — the only
HTML in the snippet output is the configured ``<mark>`` markers, so it
is safe to bypass Jinja's auto-escape.
Wires T93's `search_all_memories` service into a small read-only HTML
surface so users can find a memory across every chat in the database.
* `chat/web/search.py` (new): GET `/search?q=...` runs the FTS service
with k=50, hydrates each row with bot name + scene timestamp, and
renders `search.html`. Empty `q` short-circuits to no results so the
top-bar form can submit even with an empty input.
* `chat/templates/search.html` (new): empty-state placeholder, results
list with chat-level "Open chat" links (`/chats/{chat_id}` — memories
don't carry an event_id today, so no per-turn anchor).
* `chat/templates/layout.html`: append a small `<form>` to the rail
nav, additive only.
* `chat/app.py`: register `search_router` (additive import + include).
* `tests/test_search_ux.py`: 3 tests — multi-chat results, empty-query
placeholder, chat link.