[11.0][A3] Remove deprecated HttpDispatcher class (staged; use createDispatcherPlugin)

[os-zhuang]

Part of 11.0 breaking-change batch (#2364). Largest A-item — do in stages.

Remove the deprecated HttpDispatcher class (packages/runtime/src/http-dispatcher.ts, annotated "removed in v2"), superseded by createDispatcherPlugin().

Keep (do NOT remove)

The other exports in that file are NOT deprecated: HttpProtocolContext, HttpDispatcherResult, KernelResolver, HttpDispatcherOptions. (Also note: packages/services/service-messaging/src/http-dispatcher.ts is a different class — unrelated.)

Blast radius (~245 refs, 7 adapters)

• runtime/src/index.ts public export of HttpDispatcher
• 7 framework adapters import it: express, fastify, nextjs, nestjs, nuxt, sveltekit, hono (src/index.ts + each __mocks__/runtime.ts)
• 5–6 runtime/src/http-dispatcher*.test.ts that new HttpDispatcher(...) directly

Staged plan

1. Migrate the 7 adapters to import only the surviving types; route through createDispatcherPlugin()
2. Confirm dispatcher-plugin.ts (createDispatcherPlugin) is the canonical entry
3. Remove the public HttpDispatcher export (mark class @internal or delete); keep the 4 types exported
4. Rewrite/relocate the http-dispatcher tests to exercise the plugin
5. gen:api-surface + major changeset

Risk: high — own PR, staged, verify each adapter builds.

[os-zhuang]

Resolved via #2391 (package removal), not class removal. Investigation found HttpDispatcher is the live dispatch engine for 7 adapters + plugin-msw, and createDispatcherPlugin is a kernel route plugin — NOT a drop-in. So the issue's premise didn't hold. Instead, the 6 unused non-Hono adapters + plugin-msw were removed (zero internal consumers, undogfooded), collapsing HttpDispatcher's consumers to the Hono adapter + the internal dispatcher-plugin. The misleading @deprecated → createDispatcherPlugin note is corrected. The class is fine to keep as-is now. Closing.