feat(cli): ranked fuzzy search in the curses model picker

Wires the salvaged search helpers into the shared curses menu driver and
turns on type-to-filter for the CLI model pickers (the 100+ model lists
that previously required scrolling).

- Search lives in the shared `_run_curses_menu` driver behind a
  `searchable` flag + `search_labels`, so both `curses_radiolist` and
  `curses_single_select` get it without per-menu duplication. `/` opens
  the filter, BACKSPACE edits, Ctrl+U clears, ESC clears the filter then
  cancels. Returned values are always original item indices.
- `_filter_indices` RANKS matches (best-first) via a Python port of the
  TS scorer in ui-tui/src/lib/fuzzy.ts and web/src/lib/fuzzy.ts. The port
  is byte-identical in score: same per-char bonuses, prefix (+8) and
  exact (+20) bonuses, camelCase/word-boundary detection (matching on the
  lowercased target, boundary on the original case), and the -len*0.01
  length tiebreak — so the CLI, TUI, and WebUI rank results identically.
  A cross-language parity test pins the exact scores.
- `_prompt_model_selection` (the canonical picker across the model flows)
  and the custom-provider model list pass `searchable=True`.
- Split `_decode_menu_key` out of `read_menu_key` so the search loop can
  peek the raw key (catch `/`) before nav decoding.
- ESC during active search now clears the query (restores the full list)
  so a no-match filter can't strand the user; printable-key capture is
  restricted to ASCII to avoid Latin-1 mojibake.
- Update two setup-menu tests whose mock signatures predate the new
  `searchable` kwarg; add ranked-scorer + parity + state-machine tests.

hermes_cli/auth.py

@@ -6165,6 +6165,7 @@ def _prompt_model_selection(
             selected=default_idx,
             cancel_returns=-1,
             description=description,
+            searchable=True,
         )
         if idx < 0:
             return None