feat!: reduce devframe + @devframes/hub public API surface for 0.9 - #190

Trim both packages' published surface down to what integrations actually
consume, and move the primary authoring helper to the package root.

devframe:
- Move `defineDevframe` onto the `devframe` root entry (next to
  `defineRpcFunction`); `devframe/types` is now strictly type-only. `devframe`
  is the canonical import for both values and types.
- Remove dead subpaths: `devframe/adapters/embedded` (a one-line wrapper around
  `def.setup(ctx)`), `devframe/utils/hash`, `devframe/utils/promise`,
  `devframe/utils/scope` (no integration consumers).
- Slim `devframe/node` to the server-assembly surface, dropping 9 internal
  exports (diagnostics/services/views host classes, the shared-state/streaming/
  scope/settings factories, and the toDialableHost/formatHostForUrl helpers).
  `createContextRpcServer`, `DevframeAgentHost`, and `coerceAgentPositionalArgs`
  stay public — `@devframes/hub`'s `initHub` composes its own hand-rolled server
  and command host on them.

@devframes/hub:
- Export `DEFAULT_CATEGORIES_ORDER` only from `@devframes/hub/constants`; drop
  the redundant re-exports from `.`, `/node`, and `/client`.

All in-repo consumers (plugins, examples, packages) are migrated to the new
import paths, docs/skill/templates are swept, and `docs/guide/migration-0.9.md`
documents every change. `devframe/rpc/transports/ws-bun` is retained (the hub
uses it) despite the original plan flagging it for removal.

Co-authored-by: opencode <noreply@opencode.ai>

…rame/internal

- Restore `devframe/utils/hash` — kept as a public utility (maintainer request).
- Add a new `devframe/internal` entry point for the low-level primitives shared
  only between `devframe` and `@devframes/hub`, and relocate `createContextRpcServer`,
  `DevframeAgentHost`, and `coerceAgentPositionalArgs` there from `devframe/node`.
  `devframe/internal` is an explicitly-unstable cross-package surface; the hub
  imports these three from it. This keeps the public `devframe/node` barrel to
  the genuinely-public server-assembly API.

Updates the migration guide, SKILL/utilities docs, knip entry list, plan, and
regenerates the tsnapi snapshots.

Co-authored-by: opencode <noreply@opencode.ai>

…e/internal

Reduce the public `devframe/node` barrel to the server-assembly surface only
(`createHostContext`, `createH3DevframeHost`, `startHttpAndWs`, `createStorage`,
`RpcFunctionsHost`). Relocate the low-level primitives that only first-party
integrations use to the unstable `devframe/internal` surface:

- the instance registry (`registerDevframeInstance` / `listLiveDevframeInstances`
  + `DevframeInstanceRecord` / `DevframeInstanceRegistration`)
- `isObject`, `normalizeHttpServerUrl`

`startHttpAndWs` stays on `devframe/node` — it's the primary programmatic
server entry (used as real code by several plugins, examples, and the hub), not
a low-level util. The inspect plugin and the hub host examples now import the
instance registry from `devframe/internal`; `@vitejs/devtools` picks up
`isObject`/`normalizeHttpServerUrl` from there too.

Co-authored-by: opencode <noreply@opencode.ai>