FN-7346: fix TUI settings arrow editing

Fix Settings keyboard handling so arrow keys edit selected enum values in the terminal dashboard.

- Keep Tab as the Settings pane switcher so arrow keys remain scoped to the active pane.
- Route detail-pane left/right arrows and h/l keys through enum setting cycling and remote provider activation.
- Add terminal dashboard coverage for list navigation and enum cycling, plus CLI docs and release note coverage.

Files changed:
 .changeset/fn-7346-tui-settings-arrows.md          |   7 ++
 docs/cli-reference.md                              |   5 +
 .../commands/dashboard-tui/__tests__/app.test.tsx  | 121 ++++++++++++++++++++-
 packages/cli/src/commands/dashboard-tui/app.tsx    | 119 ++++++++++----------
 4 files changed, 186 insertions(+), 66 deletions(-)

Fusion-Task-Id: FN-7346

Fusion-Task-Lineage: c67861a7-7bb3-408d-926c-e85a44fe2dec

Co-authored-by: Fusion (runfusion.ai) <noreply@runfusion.ai>

docs/cli-reference.md

@@ -270,6 +270,11 @@ Remote actions support:
 
 > ⚠️ Remote URL/QR payloads include tokenized query data. Treat them like credentials and avoid sharing them in screenshots/chat/logs. Prefer short-lived links for ad-hoc phone login.
 
+Settings pane navigation and editing:
+- `Tab` switches focus between the settings list and the detail/edit pane.
+- In the settings list, `↑`/`↓` or `k`/`j` moves the selected setting.
+- In the detail/edit pane, `←`/`→` or `h`/`l` cycles enum values such as **Remote Provider**; `Space` toggles booleans; `+`/`-` adjusts numbers.
+
 Remote action keys in Settings detail pane:
 - `C` activate selected provider
 - `V` start tunnel