style: fix lint across client packages

eslint --fix autofixes plus manual repairs: max-len line splits
(fake-api handlers, notifier/slots JSDoc, spec signatures), charAt over
non-null-asserted indexing in slash detect/menu cores, Array.from for
code-point capping, typeof assertions for unbound-method in specs,
generic getByRole for the send-button cast, effect disposer void-wrap in
command register, and dropped unused type imports.

packages/client/ui-command/src/client/service.ts

@@ -10,8 +10,6 @@ import { Service } from 'cordis'
 import type { Context } from 'cordis'
 import type { ConnectionHandle, SessionId } from '@deepseek-ai/dsh-client-connection/client'
 import type { ClientContext, SessionsService } from '@deepseek-ai/dsh-client-runtime/client'
-// Type-only: the notice route reads ctx.conversation.input — no runtime edge.
-import type { ConversationService } from '@deepseek-ai/dsh-client-ui-conversation/client'
 import type {
   CandidateRequest, ClientSessionContext, CommandClaim, PickOutcome, SlashCandidate, SlashPick,
   SlashServiceContract, SubmitOutcome,
@@ -70,7 +68,7 @@ export class CommandService extends Service implements CommandServiceContract {
    * @returns the disposer removing the registration.
    */
   register(contribution: CommandContribution): () => void {
-    return this.ctx.effect(() => {
+    const dispose = this.ctx.effect(() => {
       const { contributions } = this.live
       if (contributions.has(contribution.name)) {
         throw new Error(`ui-command: duplicate contribution for /${contribution.name}`)
@@ -78,6 +76,7 @@ export class CommandService extends Service implements CommandServiceContract {
       contributions.set(contribution.name, contribution)
       return () => { contributions.delete(contribution.name) }
     }, 'command.register()')
+    return () => { void dispose() }
   }
 
   /**
@@ -275,7 +274,7 @@ export class CommandService extends Service implements CommandServiceContract {
   private noticeFor(id: SessionId, _name: string, level: 'info' | 'error', text: string): void {
     const actx = this.scopeFor(id)
     if (actx === undefined) return
-    const conversation = actx.get('conversation') as ConversationService | undefined
+    const conversation = actx.get('conversation')
     if (conversation === undefined) return
     conversation.input.for(actx).notify(level, text)
   }

packages/client/ui-command/tests/browser-plugin.spec.ts

@@ -62,8 +62,8 @@ describe('apply', () => {
     expect(command).toBeInstanceOf(CommandService)
     // Frozen-contract conformance (compile-time check rides the assignment).
     const contract: CommandServiceContract = command as CommandService
-    expect(contract.register).toBeTypeOf('function')
-    expect(contract.popupFor).toBeTypeOf('function')
+    expect(typeof contract.register).toBe('function')
+    expect(typeof contract.popupFor).toBe('function')
     expect([...sources.keys()]).toEqual(['/ command'])
     expect([...overlays.keys()]).toEqual(['conversation.input.overlay#command-popup'])
     await fiber.dispose()

packages/client/ui-command/tests/service.spec.ts

@@ -134,9 +134,9 @@ const req = (query: string, position: 'leading' | 'inline' = 'leading') =>
 describe('registration', () => {
   it('registers the "/" source with matchSpace/matchEnter/warm hooks and removes it on fiber disposal', async () => {
     const { registered, source, fiber } = await bench()
-    expect(source.matchSpace).toBeTypeOf('function')
-    expect(source.matchEnter).toBeTypeOf('function')
-    expect(source.warm).toBeTypeOf('function')
+    expect(typeof source.matchSpace).toBe('function')
+    expect(typeof source.matchEnter).toBe('function')
+    expect(typeof source.warm).toBe('function')
     expect([...registered.keys()]).toEqual(['/ command'])
     await fiber.dispose()
     expect(registered.size).toBe(0)