proto: freeze the wire contract at 1.0.0

Schemas for the whole v1 surface: 38 methods, 9 events, 25 named types and the
JSON-RPC envelope, with x-privileged / x-transports / x-deadlineMs / x-errors
annotations that both generators emit as data rather than prose.

Four generators over one IR (contracts/codegen/schema_ir.py), so the C++ structs,
the TypeScript types and the OpenRPC document cannot disagree about what the
contract says:

  gen_cpp.py             -> core/generated/velox_proto.{hpp,cpp}
  gen_ts.py              -> extension/src/shared/protocol/
  gen_openrpc.py         -> contracts/openrpc.json
  gen_cpp_conformance.py -> tests/conformance/cpp/fixture_dispatcher.hpp

Inbound parsing never throws: parse<T>() returns std::expected<T, ParseError> and
nlohmann's throwing ADL from_json is deliberately not emitted. Schema constraints
(minimum, maxLength, pattern, ...) become real runtime checks in both languages —
the daemon does not trust the extension and the extension does not trust the
daemon.

59 golden fixtures: a success case per method, 12 error cases, 9 events. Replayed
by tests/conformance/ against both the generated C++ and a live server over both
transports. tools/mockd serves the same fixtures with unhappy-path flags so the
GUI and EXT lanes never wait for veloxd.

run.sh also proves capture.offer fails open: with a daemon answering slower than
750 ms the client gives up and lets Firefox take the download.

core/generated/ is libveloxproto, a separate target from libveloxcore, which
still never sees JSON — see docs/adr/0009.

Co-Authored-By: Claude Opus 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_012fgjnqFCS5h5L7gZTZo3rV

tests/conformance/ts/package.json

@@ -0,0 +1,18 @@
+{
+  "name": "@velox/conformance",
+  "version": "1.0.0",
+  "private": true,
+  "description": "Replays contracts/fixtures against a live server through the generated TypeScript client.",
+  "type": "module",
+  "scripts": {
+    "conformance": "tsx replay.ts",
+    "typecheck": "tsc --noEmit"
+  },
+  "dependencies": { "ws": "^8.18.0" },
+  "devDependencies": {
+    "@types/node": "^22.7.0",
+    "@types/ws": "^8.5.12",
+    "tsx": "^4.19.0",
+    "typescript": "^5.6.0"
+  }
+}