feat: adapt to DSH 0.1.2-alpha.2 (npm-published) and bump to v0.17.2

DSH 0.1.2-alpha.2 is on npm under the `alpha` dist-tag, so the CI mount
pin and the @deepseek-ai/* devDependencies baseline move up from
0.1.1-rc.1/rc.2 (the dead dsh-client-runtime devDep goes away with
them). Verified end-to-end against a real 0.1.2-alpha.2 host: full
vitest suite (1106), typecheck, build/pack, consumer type surface, and
the headless mount smoke 14/14 — the token URL, slash RPC and
MarkdownText labels contracts are unchanged from alpha.1.

- dsh-settings dropped the runtime `settingsNamespace` export:
  namespaces are validated at compile time (SettingsNamespaceInput), so
  the host passes the 'dsh-better-sidebar' constant directly and the
  fake settings service in smoke.spec casts to the branded type.
- dsh-subagent bumped SUBAGENT_DESCRIPTOR_VERSION 2 -> 3: the version is
  stamped by the host package; the sidechat seed assertion now follows
  the constant instead of pinning a literal.
- Restored SessionEvent.ignorable and the RemoteError wrapping were
  verified to have no impact on this plugin.
- e2e scratch profiles (e2e-mount.sh / e2e-aggregate-mount.sh) add
  '@deepseek-ai/*' to minimumReleaseAgeExclude (mirroring the repo
  root): alpha releases are often <24h old when the lane runs, which
  pnpm 11's default minimumReleaseAge would refuse to install.
- vitest excludes .worktrees/** — local task worktrees carried stale
  code against the shared node_modules and broke on the devDeps bump.
- Version lockstep 0.17.2 (package.json, dsh.plugin.json,
  SIDEBAR_SERVICE_VERSION, README/AGENTS/guide docs).

src/client/service.ts

@@ -472,7 +472,7 @@ export function matchUrlTarget(tabs: readonly TabDescriptor[], url: URL): TabDes
  * The plugin version this service instance reports. Keep in lockstep with
  * `package.json`'s version — `tests/service.spec.ts` asserts the pair.
  */
-export const SIDEBAR_SERVICE_VERSION = '0.17.1'
+export const SIDEBAR_SERVICE_VERSION = '0.17.2'
 
 /**
  * Monotonic capability list consumers use to gate new API usage (features

src/index.ts

@@ -39,7 +39,7 @@ import { isTrustedApiRequest, isLoopbackHostname } from './trust-fence.ts'
 import { registerBundleRoute } from './bundle-route.ts'
 import { launchExternal } from './open-external.ts'
 import * as git from './git.ts'
-import { SettingsConflictError, settingsNamespace, type SettingsNamespace } from '@deepseek-ai/dsh-settings'
+import { SettingsConflictError } from '@deepseek-ai/dsh-settings'
 import { defaultShell, ensureSpawnHelper, PtyManager, shellDisplayName } from './pty-manager.ts'
 import { AgentPtyRegistry, clampDims, type AgentTerminalHandle } from './agent-pty.ts'
 import {
@@ -715,7 +715,10 @@ export function apply(ctx: Context, config?: SidebarConfig): void {
     }
   }
   ctx.inject(['settings'], (sctx) => {
-    const ns: SettingsNamespace = settingsNamespace(SIDEBAR_PREFS_NS)
+    // DSH 0.1.2-alpha.2 validates namespaces at compile time
+    // (SettingsNamespaceInput); the 'dsh-better-sidebar' literal passes, so the
+    // runtime helper this used to call (settingsNamespace) is gone upstream.
+    const ns = SIDEBAR_PREFS_NS
     // The structural settings mirror types `schema` as unknown, so the
     // generic is not inferred here; the real service resolves it from the
     // schemastery schema (PrefsSchema) — narrow the owner scope explicitly.