Merge latest master into manual compaction

# Conflicts:
#	apps/cli/README.i18n.yaml
#	docs/architecture.i18n.yaml
#	docs/event-producer-consumer.md
#	docs/module-graph.md
#	examples/acp-agent/tests/snapshots/cordis-inspect-jsdoc/session.jsonl
#	packages/compact/compact-basic/README.i18n.yaml
#	packages/pty/pty-local/tests/index.spec.ts

packages/core/agent-loop/src/agent.ts

@@ -35,6 +35,7 @@ import {
   LlmError,
   assertNever,
   createAssistantMessage,
+  createUserMessage,
   deepFreeze,
   errorChain,
   freezeMessage,
@@ -45,8 +46,8 @@ import {
 } from '@deepseek-ai/dsh-llm'
 import type { GenerateOptions, LlmCallConfig, LlmFailure, Message, PreparedLlmCall, ResolvedRetryPolicy } from '@deepseek-ai/dsh-llm'
 import { canonicalHeader, headerEquals } from '@deepseek-ai/dsh-session'
-import type { AssistantMessage, EpochHeader, Session, SessionId, TurnEndReason, TurnTrigger, UserMessage } from '@deepseek-ai/dsh-session'
-import { renderPrompt } from '@deepseek-ai/dsh-system-prompt'
+import type { AssistantMessage, EpochHeader, RequestContext, Session, SessionId, TurnEndReason, TurnTrigger, UserMessage } from '@deepseek-ai/dsh-session'
+import { renderContextSnapshot, renderPrompt } from '@deepseek-ai/dsh-system-prompt'
 import type {} from '@deepseek-ai/dsh-tools'
 import { executeToolCalls } from './tool-calls.ts'
 
@@ -55,6 +56,47 @@ type StepOutcome =
   | { kind: 'completed'; continueTurn: boolean; concluded: boolean; maxTokens: boolean }
   | { kind: 'request-failed'; error: RequestError; failure: LlmFailure; retryPolicy: ResolvedRetryPolicy | undefined }
 
+const RUNTIME_CONTEXT_SOURCE = '@deepseek-ai/dsh-system-prompt'
+/** Clearing marker kept distinct from every prefixed {@link renderContextSnapshot} result. */
+const CLEARED_RUNTIME_CONTEXT = 'Current runtime context: none. Earlier runtime-context snapshots no longer apply.'
+
+/** Whether one user message is owned by runtime-context materialization. */
+function isRuntimeContextMessage(message: UserMessage): boolean {
+  return message.source.kind === 'plugin' && message.source.plugin === RUNTIME_CONTEXT_SOURCE
+}
+
+/** Latest retained runtime-context snapshot; `found` distinguishes malformed content from absence. */
+function retainedRuntimeContext(session: Session): { found: boolean; text: string | undefined } {
+  const events = session.events
+  const nodes = session.surface.nodes
+  for (let index = nodes.length - 1; index >= 0; index -= 1) {
+    const event = events[nodes[index] as number]
+    if (event?.type !== 'user/message' || !isRuntimeContextMessage(event.data)) continue
+    const [block] = event.data.content
+    return {
+      found: true,
+      text: event.data.content.length === 1 && block?.type === 'text' ? block.text : undefined,
+    }
+  }
+  return { found: false, text: undefined }
+}
+
+/** Append a full current snapshot only when it changed or compaction removed it. */
+function materializeRuntimeContext(session: Session, current: string): void {
+  const previous = retainedRuntimeContext(session)
+  if (!previous.found && current.length === 0) {
+    const compactedPriorSnapshot = session.surface.replaceGeneration > 0
+      && session.events.some(event => event.type === 'user/message' && isRuntimeContextMessage(event.data))
+    if (!compactedPriorSnapshot) return
+  }
+  const snapshot = current.length === 0 ? CLEARED_RUNTIME_CONTEXT : current
+  if (previous.text === snapshot) return
+  session.append('user/message', createUserMessage({
+    content: [{ type: 'text', text: snapshot }],
+    source: { kind: 'plugin', plugin: RUNTIME_CONTEXT_SOURCE },
+  }), { surfaceOp: 'append' })
+}
+
 /** Remove adapter-derived values before plugins propose the next request config. */
 function requestProposal(header: EpochHeader): LlmCallConfig {
   if (header.adapterDefaults === undefined) return header.config
@@ -568,10 +610,13 @@ export class ReactLoopAgent implements Agent {
     // this request together.
     this.drainOutbox(turn)
 
-    // Assemble the system prompt fresh each step (it may depend on log state).
+    // Assemble request-owned prompt inputs fresh each step. Dynamic context is
+    // committed at the tail before deriving history once, preserving the stable
+    // system/history cache prefix while keeping every model-visible byte logged.
     const assembly = await this.loopCtx.systemPrompt.assemble(assembleContextFor(this, signal))
     signal.throwIfAborted()
     const system = renderPrompt(assembly)
+    materializeRuntimeContext(session, renderContextSnapshot(assembly))
 
     // Snapshot the exact log prefix: the reconstruction boundary. Appends
     // after this synchronous snapshot join the next request.
@@ -728,6 +773,24 @@ export class ReactLoopAgent implements Agent {
       session.append('request/header', { header, reason: 'change' })
     }
 
+    // TODO: This looks like code smell.
+    // Context metadata for the route this request resolved to, recorded from the same
+    // registration-bound lookup that prepared the call (no second resolve).
+    // A route with unknown capacity is still recorded so it clears any older
+    // denominator; an unchanged route logs nothing.
+    const contextWindow = preparedCall?.context?.contextWindow
+    const requestContext: RequestContext = {
+      provider: config.provider,
+      model: config.model,
+      ...contextWindow === undefined ? {} : { contextWindow },
+    }
+    const previous = session.requestContext()
+    if (previous?.provider !== requestContext.provider
+      || previous.model !== requestContext.model
+      || previous.contextWindow !== requestContext.contextWindow) {
+      session.append('request/context', requestContext)
+    }
+
     const request = markAgentLoopRequest(deepFreeze({
       ...header.config,
       messages: boundaryMessages,