docs(adr): /runda DA cleanup — reflect Phases 1-3 done, pin Bucket C

Surfaces from a Devil's-Advocate audit of the DSL → SQL teaching echo
(ADR-0038) after Phases 1-3 landed: three doc-drift bugs introduced
by the earlier handoff-47 / ADR-promotion commits — requirements.md
M4 and both ADR-0038 README index entry + Status block still said
"Phase 2 / Phase 3 remain," but `275c726` and `e6ad1ae` shipped them.
Updated to reflect actual state: Buckets A + B complete plus the
category-3 prose; only the §4 styled-runs polish remains. ADR-0037's
README entry also touched to note all four shipping commits of its
consumer.

Plus a missing test slice the DA flagged: explicit no-echo coverage
for the Bucket C cases that flow through command_to_sql's catch-all
(show table, explain, replay, every Command::App variant). The
contract — ADR-0030 §10 / ADR-0038 §7 Bucket C — forbids echoes for
these; a future renderer arm added at the wrong place could silently
leak one. The new bucket_c_no_echo_commands_all_return_none pins
that.

Tests: 2015 passed / 0 failed / 1 ignored (pre-existing); clippy
clean. Nothing to escalate.

docs/requirements.md

@@ -132,17 +132,22 @@ handoff-14 cleanup; 449 after B2/C2.)
   ADR-0030 §10 teaching echo on it: a DSL-form command run in
   advanced/one-shot mode renders the equivalent advanced-mode SQL
   beneath `[ok]`; simple-mode and SQL-entered submissions stay
-  silent. Echo coverage progress: **Bucket A complete** (Phase 1 —
-  single-statement DDL + `show data` + `--all-rows` fall-throughs,
-  every row round-tripped per ADR-0038 §1; handoff-47);
-  **Bucket B** (resolved-name + multi-line echoes — `add index`,
-  relationship add/drop, `drop column --cascade`,
-  `add relationship --create-fk`) and **category-3 prose**
-  (`shortid` generation, type-conversion transforms,
-  `change column --dont-convert` caveat) are deferred to Phase
-  2 / Phase 3 per ADR-0038 §8. The de-emphasised styled-runs
-  rendering polish (ADR-0038 §4 / ADR-0028) is also still pending —
-  the echo currently surfaces as a plain `[system]` line.
+  silent. Echo coverage: **Buckets A and B complete, plus
+  category-3 prose** — every catalogue row in ADR-0038 §7
+  round-trips per line through the advanced walker (the §1
+  copy-paste contract; §6 category 2 holds it per line). Shipped
+  across three commits: **Phase 1** Bucket A — single-statement DDL
+  + `show data` + `--all-rows` fall-throughs (`90479cb`); **Phase 2**
+  Bucket B — resolved-name + multi-line echoes (`add index` auto- and
+  user-named, positional `drop index`, `add`/`drop relationship` in
+  both selector forms, `drop column --cascade`, `add relationship
+  --create-fk`) (`275c726`); **Phase 3** the category-3 prose —
+  `shortid` generation and type-conversion transforms via the
+  pre-existing `client_side.auto_fill_*` / `client_side.transformed*`
+  notes, plus the new `change column --dont-convert` caveat
+  (`e6ad1ae`). The only remaining ADR-0038 item is the §4
+  de-emphasised **styled-runs rendering polish** (ADR-0028) — the
+  echo + caveat currently surface as plain `[system]` lines.
 
 ## App-level commands (per ADR-0003)