Merge remote-tracking branch 'origin/master' into codex/invariant-service-seam

# Conflicts:
#	.agents/notes/implemented/architecture/2026-07-19-package-owned-invariant-service.i18n.yaml
#	.agents/notes/implemented/architecture/2026-07-19-package-owned-invariant-service.md
#	.agents/notes/implemented/architecture/2026-07-19-package-owned-invariant-service.zh.md
#	.agents/notes/implemented/feature/2026-06-18-compaction-capability-seam.md
#	.agents/notes/implemented/feature/2026-07-07-session-prefix.md
#	.agents/notes/implemented/process/2026-07-14-typescript-program-backed-semantic-gates.i18n.yaml
#	docs/architecture.md
#	docs/config-catalog.md
#	docs/core-data-structures/session.md
#	docs/rfc/INDEX.md
#	packages/examples/agent-spine-demo/README.md
#	packages/examples/agent-spine-demo/src/index.ts
#	packages/examples/agent-spine-demo/tests/agent-core.spec.ts
#	packages/support/invariants/README.md
#	packages/support/invariants/src/index.ts
#	packages/support/invariants/tests/invariants.spec.ts

packages/examples/agent-spine-demo/src/index.ts

@@ -35,6 +35,8 @@ export const name = 'agent-spine-demo'
 
 /** Skill bundle config forwarded to the registry, local provider, and model-facing consumer. */
 export interface SkillConfig {
+  /** Mount the bundled local skill provider and model-facing skill tool (default true). */
+  enabled?: boolean
   /** Registry-level discovery cache settings. */
   registry?: SkillRegistryConfig
   /** Local filesystem skill provider settings. */
@@ -78,14 +80,15 @@ export interface Config {
   skills?: SkillConfig
   /** Model-facing bash tool config, including this producer's background opt-in. */
   toolBash?: toolBash.Config
-  /** Generic background-task control-tool wait bounds. */
-  toolTasks?: toolTasks.Config
+  /** Generic background-task controls; set false to keep the task service without model-facing task tools. */
+  toolTasks?: toolTasks.Config | false
   /** Global enablement and package-name filters for invariant companions. */
   invariants?: InvariantConfig
 }
 
 /** The skill config schema exported for app packages that forward `skills`. */
 export const SkillConfigSchema: z<SkillConfig> = z.object({
+  enabled: z.boolean().default(true),
   registry: SkillService.Config,
   local: SkillLocal.Config,
   tool: toolSkill.Config,
@@ -107,7 +110,7 @@ export const Config = z.intersect([
     skills: SkillConfigSchema,
     workspaceContext: z.union([z.const(false), workspaceContext.Config]).required(),
     toolBash: ToolBashConfigSchema,
-    toolTasks: ToolTasksConfigSchema,
+    toolTasks: z.union([z.const(false), ToolTasksConfigSchema]),
     invariants: InvariantService.Config,
   }) as unknown as z<Pick<Config, 'tools' | 'dshHome' | 'skills' | 'workspaceContext' | 'toolBash' | 'toolTasks' | 'invariants'>>,
 ]) as unknown as z<Config>
@@ -159,8 +162,11 @@ export function apply(ctx: Context, config: Config): void {
     ...config.toolOrder !== undefined ? { toolOrder: config.toolOrder } : {},
   })
   ctx.plugin(ToolRegistry, config.tools ?? {})
-  ctx.plugin(SkillService, config.skills?.registry ?? {})
-  ctx.plugin(SkillLocal, Object.assign({}, config.skills?.local, { dshHome }))
+  const skillsEnabled = config.skills?.enabled ?? true
+  if (skillsEnabled) {
+    ctx.plugin(SkillService, config.skills?.registry ?? {})
+    ctx.plugin(SkillLocal, Object.assign({}, config.skills?.local, { dshHome }))
+  }
   ctx.plugin(AgentRegistry)
   ctx.plugin(TaskService)
   ctx.plugin(InvariantService, config.invariants ?? {})
@@ -174,8 +180,8 @@ export function apply(ctx: Context, config: Config): void {
   }
   // Both plugins prepend session-prefix messages. Registration order is the
   // rendered order, so workspace instructions must precede the skill catalog.
-  ctx.plugin(toolSkill, config.skills?.tool ?? {})
-  ctx.plugin(toolTasks, config.toolTasks ?? {})
+  if (skillsEnabled) ctx.plugin(toolSkill, config.skills?.tool ?? {})
+  if (config.toolTasks !== false) ctx.plugin(toolTasks, config.toolTasks ?? {})
   ctx.plugin(AgentLoop, {
     agents: config.agents ?? [],
     ...config.maxParallelToolCalls !== undefined ? { maxParallelToolCalls: config.maxParallelToolCalls } : {},