Merge branch 'main' into website (Gitea migration + ADR renumber)

Brings website up to date with main (18 commits): H1a parse-error
pedagogy, V5/H3/V5a show+help commands, ADR-0043 compound-PK FK,
handoffs 58-59, and the GitHub->Gitea doc scrub (Cargo.toml repository,
CLAUDE.md, ADR-0001 amendment, requirements).

Conflict: docs/adr/README.md. main and website had each created an
ADR-0042 (main: H1a parse-error pedagogy; website: public website &
docs site). Renumbered the website ADR to 0044 (next free after main's
0042/0043) and updated all references (ADR file, plan file, STYLE.md,
astro.config.mjs, README index). Website build verified green.

docs/plans/20260604-adr-0044-website.md

@@ -3,7 +3,7 @@
 **Date:** 2026-06-04 · **Status:** ready to build
 
 Decisions for this work are recorded in
-[ADR-0042](../adr/0042-public-website-and-documentation-site.md): Astro 6 +
+[ADR-0044](../adr/0044-public-website-and-documentation-site.md): Astro 6 +
 Starlight + Tailwind v4; asciinema demos reusable in docs; the in-page WASM
 playground deferred behind a stable demo seam; portable static hosting
 (Vercel target); monorepo (`website/`); website is the canonical docs home;
@@ -128,7 +128,7 @@ project lifecycle + undo/history → Tier 3 teaching echo + EXPLAIN + errors +
 completion/highlighting → Tier 4 clipboard + hints + editing.
 
 Conventions live in the **living style guide** `website/STYLE.md` (binding
-rules from ADR-0042 §7 — no engine name, **no "DSL"**, "planned" callouts —
+rules from ADR-0044 §7 — no engine name, **no "DSL"**, "planned" callouts —
 plus finer conventions and an open-decisions log for depth/splitting/example
 dataset/etc. as they settle). Sources to mine: `src/dsl/command.rs`,
 `src/dsl/grammar/*`, the REGISTRY, `en-US.yaml`, `docs/adr/*`,
@@ -144,7 +144,7 @@ static host. `website/README.md` notes the Vercel preset (root dir
 `Demo.astro` exposes a stable contract (`{ src, title, height, autoplay }`).
 At launch it renders `Cast.astro`; later a `Playground.astro` WASM island
 swaps in behind the same props on the landing page and in docs, with zero
-call-site changes. Boundary details are in ADR-0042 §3.
+call-site changes. Boundary details are in ADR-0044 §3.
 
 ## Verification
 
@@ -155,7 +155,7 @@ call-site changes. Boundary details are in ADR-0042 §3.
 - Starlight link-check passes (broken internal links fail the build).
 - Docs grep clean of forbidden terms: **no "DSL"**, no engine name.
 - A `dist/` static deploy works on Vercel (manual import) — confirms
-  portability. (No CI gate yet, per ADR-0042 §4.)
+  portability. (No CI gate yet, per ADR-0044 §4.)
 
 ## Notes / recommendations (non-blocking)