fix(input): thread the : one-shot escape into live SQL feedback

The `:` one-shot escape (ADR-0003) is stripped at submission, but the
*live* feedback kept the leading `:` in the buffer it handed the
walker — so Tab completion, the validity verdict, and the highlight
overlays all bailed at the `:` and treated the SQL as an unknown
command. Effect: in `:`-mode, Tab completed nothing and a valid query
could flash an error, while the identical line in full `mode advanced`
worked. (The ambient hint already stripped it, which is why the hint
showed the right column name while Tab did nothing.)

Add `App::feedback_view()` — the `:`-stripped SQL view, the cursor
mapped into it, and the stripped byte offset — and route all four live
paths through it:

- completion (Tab): complete against the view, then shift the returned
  `replaced_range` back by the offset so the edit lands in the buffer;
- validity verdict: verdict the SQL, not the sigil;
- highlight/overlays: new `render_input_runs_feedback` highlights and
  diagnoses the view (shifted by the offset) while the `:` renders as
  plain text;
- ambient hint: consolidated onto `feedback_view`, replacing the
  duplicate local `strip_one_shot_prefix`.

src/ui.rs

@@ -1438,12 +1438,19 @@ fn render_input_one_row(
     let offset = input_scroll_offset(line_cols, cursor_col, tw, app.input_scroll_offset);
     app.input_scroll_offset = offset;
 
-    let runs = crate::input_render::render_input_runs_in_mode(
+    // Strip the `:` one-shot prefix for the SQL highlighting/overlays
+    // (ADR-0003); the `:` itself renders as plain text. Identity for
+    // non-one-shot input.
+    let (fb_view, fb_cursor, fb_off) = app.feedback_view();
+    let runs = crate::input_render::render_input_runs_feedback(
         &app.input,
         cursor,
         theme,
         &app.schema_cache,
         mode_for_render,
+        fb_view,
+        fb_cursor,
+        fb_off,
     );
     let spans = runs_to_spans(&app.input, &runs);
 
@@ -1507,12 +1514,19 @@ fn render_input_two_rows(
     let offset = input_scroll_offset(line_cols, cursor_col, capacity, app.input_scroll_offset);
     app.input_scroll_offset = offset;
 
-    let runs = crate::input_render::render_input_runs_in_mode(
+    // Strip the `:` one-shot prefix for the SQL highlighting/overlays
+    // (ADR-0003); the `:` itself renders as plain text. Identity for
+    // non-one-shot input.
+    let (fb_view, fb_cursor, fb_off) = app.feedback_view();
+    let runs = crate::input_render::render_input_runs_feedback(
         &app.input,
         cursor,
         theme,
         &app.schema_cache,
         mode_for_render,
+        fb_view,
+        fb_cursor,
+        fb_off,
     );
     let cells = expand_runs_to_cells(&app.input, &runs);
     let len = cells.len();
@@ -1621,23 +1635,6 @@ fn runs_to_spans<'a>(
         .collect()
 }
 
-/// Strip a leading one-shot `:` sigil (and the whitespace after
-/// it) from `input`, returning the advanced command slice and the
-/// cursor remapped into it. Mirrors `App::submit`'s `:` handling
-/// so the hint panel hints at the command, not the sigil
-/// (ADR-0022 Amendment 1). Used only when the effective mode is
-/// `AdvancedOneShot`, where `input` is guaranteed to start (after
-/// any leading whitespace) with `:`.
-fn strip_one_shot_prefix(input: &str, cursor: usize) -> (&str, usize) {
-    let lead_ws = input.len() - input.trim_start().len();
-    let after_colon = lead_ws + 1; // skip the `:`
-    let ws_after = input[after_colon..].len() - input[after_colon..].trim_start().len();
-    let prefix_len = (after_colon + ws_after).min(input.len());
-    let effective = &input[prefix_len..];
-    let effective_cursor = cursor.saturating_sub(prefix_len).min(effective.len());
-    (effective, effective_cursor)
-}
-
 /// Resolve the Hint panel body into its rendered lines, pre-wrapped
 /// to the panel's inner width and clamped to `max_rows` with an
 /// ellipsis backstop (issue #12). `max_rows` is the geometry-fixed row
@@ -1679,14 +1676,9 @@ fn resolve_hint_lines(
 
     // In one-shot advanced mode (`:` prefix in simple mode) the
     // raw input carries the `:` sigil, which is not part of the
-    // grammar. Strip it for the ambient computation so the hint
-    // reflects the advanced command — mirroring `App::submit`.
-    let (hint_input, hint_cursor) = match app.effective_mode() {
-        EffectiveMode::AdvancedOneShot => {
-            strip_one_shot_prefix(&app.input, app.input_cursor)
-        }
-        _ => (app.input.as_str(), app.input_cursor),
-    };
+    // grammar. The shared feedback view strips it so the hint reflects
+    // the advanced command — mirroring `App::submit` (ADR-0003).
+    let (hint_input, hint_cursor, _off) = app.feedback_view();
     let ambient = crate::input_render::ambient_hint_in_mode(
         hint_input,
         hint_cursor,