docs: reconcile requirements/CLAUDE.md with shipped reality (high-confidence)

Flip stale Phase-1 checkboxes whose capability is clearly delivered:
M1/M2/M3 (modes), Q1/Q2 (SQL subset — shipped via the unified walker, not
sqlparser-rs), TT1/TT2/TT3 (test tiers 1–3) → [x]; TT4 (PTY e2e, critical
flows only) → [~].

Fix stale CLAUDE.md claims: the stack no longer uses chumsky (DSL) or a
reserved sqlparser-rs (SQL) — both retired (ADR-0024 §migration Phase F);
the DSL and advanced-mode SQL are both parsed by the unified grammar
walker (ADRs 0024 / 0030–0036). Corrects the stack note, drops the
now-done "SQL handling in advanced mode" deferred bullet, and updates the
parser.rs layout comment.

Lower-confidence items (C1 rename, A1, I1a, I3, I4, T3, V2, export/import,
resume) left for a dedicated per-item reconciliation pass (handoff-45 §5).

docs/requirements.md

@@ -111,12 +111,12 @@ handoff-14 cleanup; 449 after B2/C2.)
 
 ## Input modes (per ADR-0003)
 
-- [ ] **M1** Simple mode is the default. It accepts DSL data
+- [x] **M1** Simple mode is the default. It accepts DSL data
   commands and the canonical app-level commands; raw SQL is
   rejected with a friendly hint.
-- [ ] **M2** Advanced mode accepts SQL plus the canonical
+- [x] **M2** Advanced mode accepts SQL plus the canonical
   app-level commands without any sigil.
-- [ ] **M3** Prefixing a single line with `:` in simple mode is a
+- [x] **M3** Prefixing a single line with `:` in simple mode is a
   one-shot advanced escape (with the prompt label updated). The
   `mode simple` / `mode advanced` command switches modes
   persistently.
@@ -213,7 +213,7 @@ handoff-14 cleanup; 449 after B2/C2.)
 
 ## SQL handling
 
-- [ ] **Q1** SQL parsed via `sqlparser-rs`; supported subset is
+- [x] **Q1** SQL parsed via `sqlparser-rs`; supported subset is
   defined (specifics deferred to a future ADR).
   *(Progress: the advanced-mode SQL surface is authored as grammar
   within the unified grammar tree (ADR-0030 / ADR-0024) and parsed by
@@ -260,7 +260,7 @@ handoff-14 cleanup; 449 after B2/C2.)
   word completion merge + simple/advanced completion colour; `describe` of
   table-level constraints; self-ref FK pre-submit indicator; CREATE-TABLE
   help/usage refresh). **ADR-0035 Phase 4 (4a–4i) is complete.**)*
-- [ ] **Q2** Non-standard syntax rejected with a clear message
+- [x] **Q2** Non-standard syntax rejected with a clear message
   pointing at the supported subset.
   *(Design done — ADR-0030 §8: out-of-subset statements are
   refused with an engine-neutral message naming the construct.
@@ -553,14 +553,14 @@ handoff-14 cleanup; 449 after B2/C2.)
 
 ## Testing (per ADR-0008)
 
-- [ ] **TT1** Tier 1: `cargo test` + `proptest` covering
+- [x] **TT1** Tier 1: `cargo test` + `proptest` covering
   pure-logic modules (parser, dispatcher, type mapping, project
   I/O, snapshot ring buffer, replay log).
-- [ ] **TT2** Tier 2: Ratatui `TestBackend` + `insta` snapshots
+- [x] **TT2** Tier 2: Ratatui `TestBackend` + `insta` snapshots
   for representative views.
-- [ ] **TT3** Tier 3: synthetic event-loop integration tests
+- [x] **TT3** Tier 3: synthetic event-loop integration tests
   covering the user-facing flows in this checklist.
-- [ ] **TT4** Tier 4: PTY-based end-to-end for the four critical
+- [~] **TT4** Tier 4: PTY-based end-to-end for the four critical
   flows named in ADR-0008 (cold launch → DDL → quit; save →
   reopen; export → import → rebuild; undo after DROP).
 - [ ] **TT5** CI runs all tiers on Linux, macOS, and Windows on