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/ui/acp/tests/load.spec.ts

@@ -4,6 +4,7 @@ import { tmpdir } from 'node:os'
 import { join } from 'node:path'
 import { PROTOCOL_VERSION } from '@agentclientprotocol/sdk'
 import { SessionId } from '@deepseek-ai/dsh-session'
+import { AgentId } from '@deepseek-ai/dsh-agent'
 import { makeBridgeHarness, textResponse, toolCallResponse, type BridgeHarness, type CapturedUpdate } from './harness.ts'
 
 /** Concatenate the text of all agent_message_chunk updates. */
@@ -155,7 +156,7 @@ describe('acp bridge — session/load replay', () => {
     release()                            // resume() finishes AFTER teardown
     expect(await loadResult).toBe('rejected')
     // No live agent was installed for the closed connection.
-    expect(loader.ctx.agents.get(sessionId)).toBeUndefined()
+    expect(loader.ctx.agents.get(AgentId(sessionId))).toBeUndefined()
   })
 
   it('rejects load when the requested cwd does not match the persisted session cwd', async () => {
@@ -176,11 +177,11 @@ describe('acp bridge — session/load replay', () => {
     await loader.client.initialize({ protocolVersion: PROTOCOL_VERSION, clientCapabilities: {} })
     await expect(loader.client.loadSession({ sessionId: 'elsewhere', cwd: process.cwd(), mcpServers: [] }))
       .rejects.toThrow(/cwd mismatch/)
-    expect(loader.ctx.agents.get('elsewhere')).toBeUndefined()
+    expect(loader.ctx.agents.get(AgentId('elsewhere'))).toBeUndefined()
 
     const res = await loader.client.loadSession({ sessionId: 'elsewhere', cwd: `${otherCwd}/.`, mcpServers: [] })
     expect(res).toBeDefined()
-    expect(loader.ctx.agents.get('elsewhere')!.session.header.cwd).toBe(otherCwd)
+    expect(loader.ctx.agents.get(AgentId('elsewhere'))!.session.header.cwd).toBe(otherCwd)
   })
 
   it('rejects load for a non-absolute cwd (still required to be absolute)', async () => {
@@ -215,7 +216,7 @@ describe('acp bridge — session/load replay', () => {
     // Rejected BEFORE resume (metadata-only check) — no agent was registered, so
     // the id is not wedged: a later attempt hits the same clean rejection, not a
     // duplicate-registration error.
-    expect(loader.ctx.agents.get('legacy')).toBeUndefined()
+    expect(loader.ctx.agents.get(AgentId('legacy'))).toBeUndefined()
     await expect(loader.client.loadSession({ sessionId: 'legacy', cwd: process.cwd(), mcpServers: [] }))
       .rejects.toThrow(/no absolute persisted cwd/)
   })