refactor(cli)!: one shared base config with per-surface overlays

`dsh` shipped two config trees that were 43 rows the same: apps/cli/cordis.yml
composed web as 74 flat rows, while the TUI booted examples/tui-agent/cordis.yml
whose single `@deepseek-ai/dsh-tui-demo` row mounted twelve plugins behind a
twenty-key pass-through Config. Neither file was what its location claimed —
apps/cli hardcoded the "example" as the product default and the "demo" bundle
was the application — and every capability change had to be made twice.

- apps/cli/base.cordis.yml holds the 43 shared rows; tui.cordis.yml and
  web.cordis.yml are patch lists stating only what differs per surface
- overlays apply as SIBLING patch lists at one include level, because include
  patches never cross an include boundary. Precedence: base < surface <
  (--config | personal ~/.dsh/config.yaml) < launcher flag/profile patches
- `--config` now applies an overlay INSTEAD OF the personal one, so a demo or
  test tree never inherits the user's route; new `--config-replace` boots a file
  as the entire tree (the old `--config` behaviour). Both survive /resume
- vendor/include: index each `insert`ed row as it is added so a later patch can
  configure or disable it. Upstream built the id index once before the patch
  loop, leaving every surface-only row — the whole TUI front door — silently
  unpatchable from user config. Logged as local modification 8
- session identity moves to dsh-agent-loop's CONFIGURED_AGENT_IDENTITIES_KEY;
  dsh-tui's MAIN_SESSION_ID_KEY is deleted (only the bundle read it)
- delete examples/tui-agent, examples/cordis-agent, packages/examples/tui-demo;
  TUI tests → apps/cli/tests, cordis e2e → packages/cordis/tool-cordis/tests,
  examples/code-mode survives as an overlay leaf
- `dsh web` gains --config, threaded into AppCLIEntry as an extra overlay

Three latent defects surfaced and are fixed here: the TUI captured the optional
sessionQuery service once at construction and could permanently disable /resume
when it won the mount race; the session-store root silently reverted to a
project-local ./.sessions; --config-replace was dropped by the resume handoff.

Verified by booting each tree through the real Loader (TUI 55 entries, web 75,
zero unsettled) rather than reading YAML. All eight terminal snapshots replay
byte-identically; 14/14 PTY smoke, 112/112 snapshots, 25/25 doc-sync, hygiene
and lint clean.

docs/config-catalog.md

@@ -108,7 +108,7 @@ export interface Config {
 
 Depends on: [`AgentOptions`](core-data-structures/core.md) · [`SessionId`](core-data-structures/core.md)
 
-Source: [`packages/core/agent-loop/src/index.ts:155`](../packages/core/agent-loop/src/index.ts)
+Source: [`packages/core/agent-loop/src/index.ts:211`](../packages/core/agent-loop/src/index.ts)
 
 ## `@deepseek-ai/dsh-agent-spine-demo`
 
@@ -2005,59 +2005,6 @@ export interface TuiThemeConfig {
 
 Source: [`packages/ui/tui/src/config.ts:117`](../packages/ui/tui/src/config.ts)
 
-## `@deepseek-ai/dsh-tui-demo`
-
-```ts config-catalog
-/** App config routed to the spine, TUI, configured agent, and JSONL backend. */
-export interface Config {
-  /** Provider route for the `main` agent. */
-  provider: string
-  /** Model name for the `main` agent; a matching adapter must be registered. */
-  model: string
-  /** Bundled agent-loop concurrency cap; `1` is serial and omission uses its default. */
-  maxParallelToolCalls?: number
-  /** Deployment persona forwarded to the system-prompt plugin. */
-  persona?: string
-  /** Explicit model-facing tool order forwarded to the system-prompt plugin. */
-  toolOrder?: string[]
-  /** Tool-registry presentation config forwarded through agent-spine-demo. */
-  tools?: ToolsConfig
-  /** DeepSeek Harness home directory exposed to bash and used for local skill discovery. */
-  dshHome?: string
-  /** Fallback session-title limits forwarded through agent-spine-demo. */
-  sessionTitle?: NonNullable<agentCore.Config['sessionTitle']>
-  /**
-   * Directory for JSONL sessions and the derived query index. Precedence:
-   * this explicit config, then the launcher's opaque `SESSIONS_ROOT_KEY` boot
-   * slot (the dsh CLI resolves it to `DSH_HOME/sessions`), then a project-local
-   * `./.sessions` fallback — the bundle itself never assumes a global store.
-   */
-  persistenceRoot?: string
-  /** JSONL artifact encoding; defaults to checksummed Zstandard frames. */
-  persistenceCompression?: JsonlCompression
-  /** Cross-session reference discovery and snapshot byte budgets. */
-  sessionReferences?: SessionReferenceConfig
-  /** TUI transcript's optional first line; absent renders nothing on start. */
-  welcome?: string
-  /** Full-screen TUI presentation settings. */
-  ui?: uiTui.TuiConfig
-  /** Skill registry, local-provider, and model-facing consumer config. */
-  skills?: agentCore.SkillConfig
-  /** Model-facing bash tool config forwarded through agent-spine-demo. */
-  toolBash?: NonNullable<agentCore.Config['toolBash']>
-  /** Generic background-task controls forwarded through agent-spine-demo; set false to omit them. */
-  toolTasks?: NonNullable<agentCore.Config['toolTasks']>
-  /** Persisted same-session goals; owner defaults enable them, or false disables the stack and command. */
-  goals?: agentCore.GoalConfig | false
-  /** Controls automatic AGENTS.md/CLAUDE.md loading; configure a byte budget or set `false`. */
-  workspaceContext: agentCore.Config['workspaceContext']
-}
-```
-
-Depends on: [`agentCore`](../packages/examples/agent-spine-demo/src/index.ts) · [`JsonlCompression`](../packages/session-persistence/session-persistence-jsonl/src/index.ts) · [`SessionReferenceConfig`](#deepseek-aidsh-session-reference) · [`ToolsConfig`](#deepseek-aidsh-tools) · [`uiTui`](../packages/ui/tui/src/index.ts)
-
-Source: [`packages/examples/tui-demo/src/index.ts:44`](../packages/examples/tui-demo/src/index.ts)
-
 ## `@deepseek-ai/dsh-user-approval`
 
 ```ts config-catalog