docs: withdraw multi-tab output from scope (S3/V2 → satisfied)

The trailing "multiple tabs" clause of S3 and V2 is dropped from
tracked scope by user decision. The output pane is settling on the
single scrollable V4 journal model rather than switchable result
tabs, so both items are now fully satisfied (the table view and
single-element visualisation were already built). V4 noted as the
sole tracked direction for evolving the output pane. A future
return to tabbed output would be a fresh requirement.

No ADR touched: multi-tab output never had a deciding ADR.

docs/requirements.md

@@ -88,12 +88,16 @@ since ADR-0027.)
   because relationships are cross-table rather than per-table, they
   get their own sibling panel stacked below the tables list, not
   nested items within it — user-confirmed 2026-06-10.)*
-- [/] **S3** Output panel renders a visualization of the
-  currently selected item and supports multiple tabs.
-  *(Partial, verified 2026-06-07: single-element structure
-  visualisation renders (`output_render.rs:82-180`); **multiple
-  tabs are not implemented** — the output is one line buffer, no
-  tab abstraction. Same multi-tab gap as V2.)*
+- [x] **S3** Output panel renders a visualization of the
+  currently selected item.
+  *(Satisfied: single-element structure visualisation renders
+  (`output_render.rs:82-180`) — select a table, see its columns /
+  types / keys. **Multi-tab clause withdrawn 2026-06-11** (user
+  decision): the original wording promised "and supports multiple
+  tabs", but the output model is settling on the single scrollable
+  **V4 journal** rather than switchable tabs, so the tab clause is
+  dropped from tracked scope. A future return to tabbed output would
+  be a fresh requirement, not this one. Same withdrawal as V2.)*
 - [x] **S4** Hint area below the input field, showing hints about
   the current input or last error.
   *(Verified 2026-06-07: `ui.rs:1088-1110` `render_hint_panel` /
@@ -469,15 +473,18 @@ since ADR-0027.)
   "relationship-relevant" reach). The §3 last-resort helper line was
   considered and rejected. Two `/runda` passes (design + implementation).
   Selection-nav and the broader journal direction remain in V4.)*
-- [/] **V2** SQL query results render as a dynamic table view in
-  the output pane, with multiple result tabs supported.
-  *(Partial, verified 2026-06-07: the **table view** is done —
-  `output_render.rs:38-72` `render_data_table` renders a
-  box-drawing frame with aligned columns (numeric right, text
-  left) and NULL/control-char sanitisation, for `show data` and
-  after every write (ADR-0014). **Missing: multiple result tabs**
-  — the output is a single `VecDeque<OutputLine>` with no tab
-  abstraction (same gap as S3). Multi-tab sits in V4 territory.)*
+- [x] **V2** SQL query results render as a dynamic table view in
+  the output pane.
+  *(Satisfied: the **table view** is done — `output_render.rs:38-72`
+  `render_data_table` renders a box-drawing frame with aligned
+  columns (numeric right, text left) and NULL/control-char
+  sanitisation, for `show data` and after every write (ADR-0014).
+  **Multi-tab clause withdrawn 2026-06-11** (user decision): the
+  original wording promised "with multiple result tabs supported";
+  retained multi-result output, if ever wanted, now belongs to the
+  single scrollable **V4 journal** direction rather than switchable
+  tabs, so the tab clause is dropped from tracked scope. A future
+  return would be a new requirement. Same withdrawal as S3.)*
 - [~] **V3** Full ER-diagram export (whole-database graph, viewed
   outside the TUI) — low priority; design and ADR pending.
 - [~] **V4** Output panel as a *scrollable per-session log* with
@@ -492,7 +499,13 @@ since ADR-0027.)
   *(Partial: PageUp / PageDown scrolling of the existing line
   buffer is in, with new output snapping the view to the most
   recent. The full V4 scope — smart structure rendering, log
-  styling, Markdown export, scroll indicator — remains pending.)*
+  styling, Markdown export, scroll indicator — remains pending.
+  **As of 2026-06-11 this journal model is the sole tracked
+  direction for evolving the output pane:** the competing multi-tab
+  output alternative (the trailing clauses of S3 and V2) was
+  withdrawn from scope by user decision, so retained / multi-result
+  output, if pursued, is folded into this journal rather than into
+  switchable tabs.)*
 - [x] **V5** `show <kind> [<name>]` family of commands for
   redisplaying schema info on demand.
   *(Done 2026-06-07: `show table <name>` + `show data <Table>`