Merge remote-tracking branch 'origin/master' into codex/project-instruction-files

# Conflicts:
#	docs/config-catalog.md
#	docs/cordis-catalog/events.md
#	docs/cordis-catalog/services.md
#	docs/core-data-structures/core.md
#	docs/event-producer-consumer.md
#	docs/persistence-catalog.md
#	docs/rfc/implemented/feature/2026-06-15-code-mode.md
#	docs/rfc/implemented/feature/2026-06-30-interception-seams.md
#	docs/rfc/proposed/simplification/2026-07-04-prune-dead-core-spine-surface.md
#	docs/tool-execution-pipeline.md
#	packages/cordis/tool-cordis/src/api-catalog.ts
#	packages/core/agent-core/tests/agent-core.spec.ts
#	packages/core/agent-loop/src/agent.ts
#	packages/core/agent/README.md
#	packages/core/session/src/index.ts
#	packages/core/tools/README.md
#	packages/core/tools/src/index.ts
#	pnpm-lock.yaml
#	scripts/gen-doc-graphs.ts
#	scripts/type-equiv.manifest.json

packages/core/tools/src/schema.ts

@@ -287,21 +287,21 @@ export function validateArgs(spec: SchemaSpec, args: unknown): string[] {
 /** Options for {@link defineTool}. */
 export interface DefineToolOptions<S extends SchemaSpec> {
   /** Tool name (must be unique). */
-  name: string
+  readonly name: string
   /** Human-readable description sent to the model. */
-  description: string
+  readonly description: string
   /**
    * Parameter schema using the per-property-required DSL. Converted to
    * standard JSON Schema at runtime.
    */
-  parameters: S
+  readonly parameters: S
   /**
    * Optional cooperative tool-call timeout budget in milliseconds. When given it
    * must be a positive finite number; it is attached to the produced
    * {@link ToolDefinition} for `@deepseek-ai/dsh-timeout-policy` to enforce and
    * is never sent to the model.
    */
-  timeoutMs?: number
+  readonly timeoutMs?: number
   /**
    * Tool execution function. `args` is typed as {@link InferArgs<S>} — zero
    * casts needed. Returns either a bare {@link ContentBlock}`[]` (model-facing
@@ -353,6 +353,7 @@ export interface DefineToolOptions<S extends SchemaSpec> {
  * Raw JSON-Schema tool definitions (from MCP servers) are still accepted
  * by `ToolRegistry.register()` directly — `defineTool` is sugar for
  * first-party plugin authors.
+ *
  * @param options - the tool's name, description, typed parameter schema,
  *   execute body, and optional presenters.
  * @returns a registry-ready {@link ToolDefinition}: its `execute` validates the