feat(types): brand bash ids + stop brand erosion; extract Branded to dsh-brand

Type-only change (brands are zero-cost casts; no runtime/wire impact). Closes
the two gaps in the "brand ids that cross package boundaries" policy and fixes
the dependency direction so a capability package never pulls in an unrelated one.

- Extract the `Branded<B>` primitive into a new standalone type-only package
  `@deepseek-ai/dsh-brand` (packages/util/brand) with no harness-package deps.
  dsh-llm keeps its owned CallId but imports Branded from dsh-brand; dsh-session,
  dsh-agent, and dsh-bash all import Branded from there. dsh-bash depends on
  dsh-brand ALONE — never on dsh-llm or dsh-session (the architectural fix: a
  generic execution backend must not couple to the LLM or session vocabulary).
- Mint BashTaskId + OwnerToken in dsh-bash and thread them through BashTask.id,
  the get/ownerOf/list/readOutput/kill seam, the bash-local generation site, and
  the dsh-tool-bash validate/access surface. OwnerToken is a DISTINCT brand from
  SessionId so the seam stays decoupled; dsh-tool-bash is the single boundary
  that casts SessionId -> OwnerToken.
- Brand at the SOURCE, not via mid-pipeline casts: agent-loop's Config types
  agents[].id as AgentId and resumeSessionId as SessionId, so the brand enters
  at the config boundary and the inner create()/resume casts disappear (only the
  genuinely-new per-run session-id string is cast).
- Stop brand erosion: propagate CallId/SessionId/AgentId to the registry/store
  Map keys and public params/exports (SessionStore, AgentRegistry + factory
  options, the ACP session-id surface + ToolPresenter CallId map, the
  persistence coordinator, invariants pendingCalls, the pi-ai tool-call maps).
- Docs: document BashTaskId/OwnerToken in bash.md (type-equiv re-pasted), point
  the Branded type-equiv at dsh-brand, fix stale param types in the session/
  agent/bash READMEs, regenerate the cordis catalog + module graph.

Implements docs/rfc/proposed/architecture/2026-06-20-branded-ids.md

packages/bash/tool-bash/tests/integration.spec.ts

@@ -5,9 +5,10 @@ import SessionStore from '@deepseek-ai/dsh-session'
 import type { SessionEvent } from '@deepseek-ai/dsh-session'
 import SystemPrompt from '@deepseek-ai/dsh-system-prompt'
 import ToolRegistry from '@deepseek-ai/dsh-tools'
-import AgentRegistry from '@deepseek-ai/dsh-agent'
+import AgentRegistry, { AgentId } from '@deepseek-ai/dsh-agent'
 import AgentLoop, { ReactLoopAgent } from '@deepseek-ai/dsh-agent-loop'
 import { LocalBashExecutor } from '@deepseek-ai/dsh-bash-local'
+import { BashTaskId } from '@deepseek-ai/dsh-bash'
 import * as ToolBash from '@deepseek-ai/dsh-tool-bash'
 import { MockAdapter, textResponse, toolCallResponse } from '../../../core/agent-loop/tests/mock-adapter.ts'
 
@@ -73,7 +74,7 @@ describe('bash tool through the agent loop', () => {
       textResponse('The command printed integration-ok.'),
     ])
     const ctx = await harness(adapter)
-    const agent = ctx.agentLoop.create('it-fg', { model: 'mock' })
+    const agent = ctx.agentLoop.create(AgentId('it-fg'), { model: 'mock' })
 
     agent.send([{ type: 'text', text: 'run echo integration-ok' }])
     await waitForIdle(ctx, agent)
@@ -105,7 +106,7 @@ describe('bash tool through the agent loop', () => {
       textResponse('It failed with code 9.'),
     ])
     const ctx = await harness(adapter)
-    const agent = ctx.agentLoop.create('it-exit', { model: 'mock' })
+    const agent = ctx.agentLoop.create(AgentId('it-exit'), { model: 'mock' })
 
     agent.send([{ type: 'text', text: 'run exit 9' }])
     await waitForIdle(ctx, agent)
@@ -126,7 +127,7 @@ describe('bash tool through the agent loop', () => {
     let taskId = ''
 
     const ctx = await harness(adapter)
-    const agent = ctx.agentLoop.create('it-bg', { model: 'mock' })
+    const agent = ctx.agentLoop.create(AgentId('it-bg'), { model: 'mock' })
 
     // Intercept the first tool result to capture the generated task id, then
     // rewrite the second scripted call's arguments to use it.
@@ -147,7 +148,7 @@ describe('bash tool through the agent loop', () => {
     await waitForIdle(ctx, agent)
 
     // Wait for the background task itself (completion may race turn end).
-    const task = ctx.bash.get(taskId)
+    const task = ctx.bash.get(BashTaskId(taskId))
     if (!task) throw new Error(`task ${taskId} not registered`)
     await task.done