docs(x): design docs and prompt catalogs follow the runtime/ move

Path pass over turn-runtime-design.md, session-design.md,
VIDEO_MODE.md, and LIVE_NOTE.md: every source pointer updated to the
runtime/ layout, the turn doc's suggested-module-layout section (§28)
refreshed to the real tree (it predated the event hub, bridges, and
composer), and the session doc's §14 layout fixed including its old
§11/§14 contradiction about where the headless runner lives.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

apps/x/LIVE_NOTE.md

@@ -326,7 +326,7 @@ Three branches by `trigger`:
 ### 5. Live Note skill (Copilot-facing)
 
 - **Purpose**: teaches Copilot the `live:` model — operational posture (act-first), the strong/medium/anti-signal taxonomy and how to act on each, the **always-extend-not-fork** rule for already-live notes, user-facing language (call them "live notes"; surface the **Live Note panel** by name), the auto-run-once-on-create/edit default, schema, triggers, YAML-safety rules, insertion workflow, and the `run-live-note-agent` tool with `context` backfills.
-- **File**: `packages/core/src/application/assistant/skills/live-note/skill.ts`. Exported `skill` constant.
+- **File**: `packages/core/src/runtime/assembly/skills/live-note/skill.ts`. Exported `skill` constant.
 - **Schema interpolation**: at module load, `stringifyYaml(z.toJSONSchema(LiveNoteSchema))` is interpolated into the "Canonical Schema" section. Edits to `LiveNoteSchema` propagate automatically.
 - **Output**: markdown, injected into the Copilot system prompt when `loadSkill('live-note')` fires.
 - **Invoked by**: Copilot's `loadSkill` builtin tool. Registration in `skills/index.ts`.
@@ -334,7 +334,7 @@ Three branches by `trigger`:
 ### 6. Copilot trigger paragraph
 
 - **Purpose**: tells Copilot *when* to load the `live-note` skill, and frames how aggressively to act once loaded.
-- **File**: `packages/core/src/application/assistant/instructions.ts` (look for the "Live Notes" paragraph).
+- **File**: `packages/core/src/runtime/assembly/copilot/instructions.ts` (look for the "Live Notes" paragraph).
 - **Strong signals (load + act without asking)**: cadence words ("every morning / daily / hourly…"), living-document verbs ("keep a running summary of…", "maintain a digest of…"), watch/monitor verbs, pin-live framings ("always show the latest X here"), direct ("track / follow X"), event-conditional ("whenever a relevant email comes in…").
 - **Medium signals (load + answer the one-off + offer)**: time-decaying questions ("what's the weather?", "USD/INR right now?", "service X status?"), note-anchored snapshots ("show me my schedule here"), recurring artifacts ("morning briefing", "weekly review", "Acme dashboard"), topic-following / catch-up.
 - **Anti-signals (do NOT make live)**: definitional questions, one-off lookups, manual document editing.
@@ -343,7 +343,7 @@ Three branches by `trigger`:
 ### 7. `run-live-note-agent` tool — `context` parameter description
 
 - **Purpose**: a mini-prompt (a Zod `.describe()`) that guides Copilot on when to pass extra context for a run.
-- **File**: `packages/core/src/application/lib/builtin-tools.ts` (the `run-live-note-agent` tool definition).
+- **File**: `packages/core/src/runtime/tools/catalog.ts` (the `run-live-note-agent` tool definition).
 - **Inputs**: `filePath` (workspace-relative; the tool strips the `knowledge/` prefix internally), optional `context`.
 - **Output**: flows into `runLiveNoteAgent(..., 'manual')` → `buildMessage` → appended as `**Context:**` in the agent message.
 - **Key use case**: backfill a newly-made-live note so its body isn't empty on day 1.
@@ -394,10 +394,10 @@ Conventions:
 | Deprecated Today.md one-time migration | `packages/core/src/knowledge/deprecate_today_note.ts` |
 | Gmail event producer | `packages/core/src/knowledge/sync_gmail.ts` |
 | Calendar event producer + digest | `packages/core/src/knowledge/sync_calendar.ts` |
-| Copilot skill | `packages/core/src/application/assistant/skills/live-note/skill.ts` |
-| Skill registration | `packages/core/src/application/assistant/skills/index.ts` |
-| Copilot trigger paragraph | `packages/core/src/application/assistant/instructions.ts` |
-| `run-live-note-agent` builtin tool | `packages/core/src/application/lib/builtin-tools.ts` |
+| Copilot skill | `packages/core/src/runtime/assembly/skills/live-note/skill.ts` |
+| Skill registration | `packages/core/src/runtime/assembly/skills/index.ts` |
+| Copilot trigger paragraph | `packages/core/src/runtime/assembly/copilot/instructions.ts` |
+| `run-live-note-agent` builtin tool | `packages/core/src/runtime/tools/catalog.ts` |
 | Editor toolbar (Radio button → panel) | `apps/renderer/src/components/editor-toolbar.tsx` |
 | Live Note panel (single-view editor) | `apps/renderer/src/components/live-note-sidebar.tsx` |
 | Status hook (`useLiveNoteAgentStatus`) | `apps/renderer/src/hooks/use-live-note-agent-status.ts` |

apps/x/VIDEO_MODE.md

@@ -108,7 +108,7 @@ is live) to the outgoing message as `UserImagePart`s and sets
   (`data`, `mediaType`), `source: 'camera' | 'screen'`, `capturedAt`. Unlike
   file attachments (path references read via the `LLMParse` tool), image
   parts go to the model as real multimodal image parts.
-- `packages/core/src/agents/message-encoding.ts` `convertFromMessages`:
+- `packages/core/src/runtime/assembly/message-encoding.ts` `convertFromMessages`:
   emits a context line (frame counts + time span), then labeled groups —
   a `"Webcam frames (oldest to newest):"` text part before camera images and
   a `"Screen-share frames (oldest to newest):"` text part before screen
@@ -176,11 +176,11 @@ Push-to-talk is disabled while a call owns the mic.
 
 | Prompt | Where |
 |--------|-------|
-| `# Video Mode (Live Camera)` system section — how to use webcam frames, coaching guidance, screen-share rules ("treat the screen as the primary subject", "last screen frame is current"), etiquette (never comment on appearance) | `packages/core/src/application/assistant/capabilities/modes.ts` (the `VIDEO_MODE` fragment of the `video-mode` capability, composed by `agents/compose-instructions.ts`) |
+| `# Video Mode (Live Camera)` system section — how to use webcam frames, coaching guidance, screen-share rules ("treat the screen as the primary subject", "last screen frame is current"), etiquette (never comment on appearance) | `packages/core/src/runtime/assembly/capabilities/modes.ts` (the `VIDEO_MODE` fragment of the `video-mode` capability, composed by `agents/compose-instructions.ts`) |
 | `# Practice Session (Coach Mode)` system section — coaching persona: specific/actionable feedback after each take, one-sentence interjections mid-flow, structured debrief on wrap-up | `capabilities/modes.ts` (the `COACH_MODE` fragment, directly after the video capability) |
-| "Driving the app" paragraph in the video-mode section — on calls, prefer app-navigation read-view/open-item (show while telling) over describing or squinting at frames | same `# Video Mode` section; full action docs in the `app-navigation` skill (`application/assistant/skills/app-navigation/skill.ts`) |
-| Per-message frame context line `[Video mode: N live webcam frames … and M frames of the user's shared screen …]` + group labels | `packages/core/src/agents/runtime.ts` (`convertFromMessages`) |
-| `videoMode` / `coachMode` composition overrides (session-sticky; flips bust prefix cache) | `packages/core/src/turns/bridges/real-agent-resolver.ts` (`CompositionOverrides`); set from `App.tsx` `sendConfig` |
+| "Driving the app" paragraph in the video-mode section — on calls, prefer app-navigation read-view/open-item (show while telling) over describing or squinting at frames | same `# Video Mode` section; full action docs in the `app-navigation` skill (`runtime/assembly/skills/app-navigation/skill.ts`) |
+| Per-message frame context line `[Video mode: N live webcam frames … and M frames of the user's shared screen …]` + group labels | `packages/core/src/runtime/legacy/engine.ts` (`convertFromMessages`) |
+| `videoMode` / `coachMode` composition overrides (session-sticky; flips bust prefix cache) | `packages/core/src/runtime/turns/bridges/real-agent-resolver.ts` (`CompositionOverrides`); set from `App.tsx` `sendConfig` |
 
 Voice input/output prompt sections (`# Voice Input`, `# Voice Output`) are
 reused untouched — calls set `voiceInput` per utterance and force

apps/x/packages/core/docs/session-design.md

@@ -520,16 +520,21 @@ All tests use the in-memory/mocked turn runtime and repo fakes.
 ## 14. Suggested module layout
 
 ```text
-apps/x/packages/shared/src/sessions.ts   # event schemas, reducer, index types
+apps/x/packages/shared/src/sessions.ts        # event schemas, reducer, index types
 
-apps/x/packages/core/src/sessions/
+apps/x/packages/core/src/runtime/sessions/
   sessions.ts      # ISessions implementation
+  api.ts           # public contract
   repo.ts          # ISessionRepo contract
   fs-repo.ts       # filesystem implementation
-  index.ts         # in-memory index + startup scan
-  headless.ts      # runHeadlessTurn
+  session-index.ts # in-memory index
+  bus.ts           # index-changed fan-out
 ```
 
+The headless helper of §11 is implemented as `HeadlessAgentRunner` in
+`runtime/assembly/headless.ts` (not under `sessions/`).
+
+
 Awilix registration mirrors the turn runtime: singleton scope, PROXY
 constructor injection, no container resolution from inside the classes.
 

apps/x/packages/core/docs/turn-runtime-design.md

@@ -1888,21 +1888,20 @@ tests for:
 This is a suggested organization, not a locked implementation requirement:
 
 ```text
-apps/x/packages/shared/src/turns.ts
+apps/x/packages/shared/src/turns.ts   # durable schemas + reducer (unchanged home)
 
-apps/x/packages/core/src/turns/
-  runtime.ts
-  reducer.ts              # if implementation is re-exported through shared,
-                          # locate pure code to avoid dependency cycles
-  repo.ts
-  fs-repo.ts
-  stream.ts
-  agent-resolver.ts
-  context-resolver.ts
-  model-registry.ts
-  tool-registry.ts
-  permission.ts
-  index.ts
+apps/x/packages/core/src/runtime/
+  turns/          # the engine: runtime.ts, stream, event-hub, context
+                  # resolution/elision, request composer, repos, inspect-cli
+    bridges/      # real implementations of the engine's seams (agent/tool/
+                  # model resolvers, permission checker/classifier)
+  sessions/       # session layer (session-design.md)
+  assembly/       # what an agent is: registry, compose-instructions,
+                  # workspace-context, message-encoding, permission-metadata,
+                  # headless runners, spawn-agent, copilot/, capabilities/,
+                  # skills/
+  tools/          # builtin-tool catalog + domain modules + exec plumbing
+  legacy/         # the dying runs engine (engine.ts + runs.ts + repos)
 ```
 
 The final reducer location must permit both core and renderer to use exactly the