The dispatch-layer mode gate (previous commit) made the submit
behaviour correct — `select` runs in advanced mode and shows
the SQL hint in simple mode. This commit extends that gating to
the ambient assistance layer so simple-mode users do not see
SQL leak through Tab completion, the live error overlay, or the
`[ERR]`/`[WRN]` validity indicator either.
`_in_mode` walker variants
--------------------------
- `completion_probe_in_mode`, `expected_at_input_in_mode`,
`input_verdict_in_mode`. Each sets `ctx.mode` before walking.
The empty-input / unknown-entry fallback in `completion_probe`
and `expected_at_input` filters the `REGISTRY` listing by
`is_advanced_only` so Tab does not offer `select` in simple
mode. Old signatures keep delegating to `Mode::Advanced`
(back-compat for tests + other callers).
`_in_mode` completion variants
------------------------------
- `candidates_at_cursor_in_mode`, `candidates_at_cursor_with_in_mode`.
Internally they route the `parse_command` completeness probe
through `parse_command_in_mode(input, mode)`, the
`completion_probe` call through `completion_probe_in_mode`,
and the `expected_at` fallback through
`expected_at_input_in_mode`. Old signatures default to
`Mode::Advanced`.
`EffectiveMode::as_mode`
------------------------
- Collapses the persistent / one-shot distinction the UI cares
about into the plain `Mode` the walker reads from
`WalkContext::mode`. App-level call sites that thread mode
into the walker chain use this.
App / input-render wiring
-------------------------
- `App::input_validity_verdict` runs only when effective mode
is plain `Simple` (per ADR-0027), so it hardcodes
`Mode::Simple` into the new `input_verdict_in_mode` call
rather than threading.
- `App::start_or_complete_at` / `_last` (the Tab handlers)
pass `self.effective_mode().as_mode()` into
`candidates_at_cursor_in_mode`, so a `:` one-shot or
persistent advanced gives full SQL completion, persistent
simple does not offer SQL.
- `input_render::render_input_runs` and `ambient_hint` are
invoked from `ui.rs` only when effective mode is plain
`Simple` (advanced rendering uses `plain_input_spans` and
skips ambient hinting per ADR-0022 §12). Their internal
`classify_input_with_schema` / `candidates_at_cursor` /
`parse_command` calls now go through the mode-aware variants
with `Mode::Simple` hardcoded — a SQL form in simple mode
surfaces as a definite-error overlay and the hint panel does
not offer it.
After this commit a simple-mode user typing `select` or
`sel<Tab>` sees nothing SQL-shaped: no live highlight, no Tab
completion candidate, the `[ERR]` indicator lit, and the on-
submit hint that names the recovery paths. An advanced-mode
user or a `:` one-shot sees the full SQL surface.
claude@clouddev1
83e0ddc2ff