feat(memory): give the memory panel search, filtering and paging

[sulthannauval]

Problem

Driving the panel against a 121-entry store — rather than reading it — the
header said "100 of 121" and the list simply stopped. The remaining 21
were unreachable by any control on the page, although api.memory() already
took an offset and the gateway already honoured it. The capability was there;
the panel never asked for it.

Alongside that: no search (the CLI and the TUI both search), no category
filter (though every row shows a category badge and the store form has a
category picker), long entries clamped to three lines with no way to read the
rest, and no way to name an entry the API would happily have named.

And one object went by five names on a single screen — Memory, Facts, Memory
entries, "a fact", "this memory".

Change

• Paging. 50 per page, Previous/Next, and a range that says which rows are
  on screen. Every entry is reachable.
• Search, debounced, through the gateway's new ?q=, so results come back
  ranked; matches show their relevance.
• Category filter, matching the badges and picker already present.
• Show more on long entries instead of a silent clamp.
• Optional name in the store form. Naming is what makes an entry
  addressable from the CLI and API afterwards; unnamed ones get a UUID that
  reads as noise.
• One vocabulary. It is a memory; the verbs are Remember and Forget.

Depends on

RantAIClaw #415 (?q= and ?category= on GET /api/v1/memory). Without it
the two new controls return unfiltered results.

Validation

npx tsc --noEmit clean, npm run build clean, then driven in a real browser
against a live gateway holding 123 entries:

Action	Result
baseline	Memories · 1–50 of 123
Next, Next	51–100 of 123, then 101–123 of 123, Next disabled
search roadmap	1–1 of 1 matching, the roadmap entry
filter daily	1–3 of 3 matching, only daily badges
search deployment	1–50 of 119 matching; page 2 still of 119
Show more	clamp drops, 57.75px → 77px, aria-expanded=true

The stable total across search pages is worth noting: an earlier read said
"1–50 of 50" and that turned out to be a stale gateway binary, not the
panel. Restarting it against the current build gave 119 on both pages.

Risk / rollback

Low: three files, one panel. Revert the commit. The two new query params are
additive server-side, so an older gateway degrades to unfiltered results
rather than erroring.