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/core/agent-loop/tests/properties.spec.ts

@@ -17,7 +17,7 @@ import { LlmAdapter } from '@deepseek-ai/dsh-llm'
 import SessionStore 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, { type ReactLoopAgent } from '@deepseek-ai/dsh-agent-loop'
 import fc from 'fast-check'
 
@@ -95,7 +95,7 @@ describe('agent loop scheduling properties', () => {
       async (texts) => {
         const ctx = await harness()
         try {
-          const agent = ctx.agentLoop.create('a', { model: 'mock' })
+          const agent = ctx.agentLoop.create(AgentId('a'), { model: 'mock' })
           const { seen: trace } = recordStatus(ctx, agent)
           const idle = nextIdle(ctx, agent)
           // Send all in one synchronous tick: they queue before the loop wakes.
@@ -120,7 +120,7 @@ describe('agent loop scheduling properties', () => {
       async (texts) => {
         const ctx = await harness()
         try {
-          const agent = ctx.agentLoop.create('a', { model: 'mock' })
+          const agent = ctx.agentLoop.create(AgentId('a'), { model: 'mock' })
           for (const text of texts) {
             const idle = nextIdle(ctx, agent)
             agent.send([{ type: 'text', text }])
@@ -145,7 +145,7 @@ describe('agent loop scheduling properties', () => {
       async (steps) => {
         const ctx = await harness()
         try {
-          const agent = ctx.agentLoop.create('a', { model: 'mock' })
+          const agent = ctx.agentLoop.create(AgentId('a'), { model: 'mock' })
           // Capture an idle waiter before EACH send; the last one is guaranteed
           // to resolve because the final send always triggers (or joins) a turn
           // that ends idle. Awaiting an already-resolved waiter is a no-op, so a