fix(sparql): require data:write for SPARQL UPDATE

[EthanThatOneKid]

What

POST /worlds/{worldId}/sparql authorized every request with data:read, so a key issued with ["data:read"] could run INSERT DATA, DELETE WHERE, DROP ALL and so on, and mutate or wipe a world. Fixes #138.

• The route now parses the query with the engine's own parser (@wazoo/sparql-engine/parser, default options, same as WazooSparqlEngine). It requires data:write for an update and data:read for a query. The decision is made before execution, not from the result kind.
• An unparseable query returns 400 INVALID_ARGUMENT without reaching the engine.
• The namespace and world check still runs first, so a foreign key gets 403 without any feedback about its query.

Tests

tests/abuse.test.ts, under "scope enforcement":

• A data:read key gets 403 naming data:write for each of 7 update forms (INSERT DATA, DELETE DATA, DELETE WHERE, INSERT … WHERE, DELETE/INSERT … WHERE, CLEAR, DROP), and the SDK is never called.
• A data:read key can still run SELECT and ASK.
• A data:read+data:write key and the admin key can run updates.
• An unparseable query returns 400 and is never executed.

I ran the new tests against the unfixed route: the 7 update cases and the unparseable case fail there. With the fix, the full suite passes (226 tests) and typecheck is clean.

Not observed

• I didn't run this against a deployed environment. deploy-qa and health-qa run only on push to main.
• I didn't change the OpenAPI description. It still says the route accepts "SELECT, ASK, or UPDATE" without naming scopes. Documenting the scope split belongs in docs.wazoo.dev.
• Downstream: no contract or schema change. Clients that send updates with a read-only key will now get 403, which is the intended behavior.

🤖 Generated with Claude Code