Handoff-style /model switch command and per-turn thinking level (#64)

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

packages/server/src/api/types.ts

@@ -473,6 +473,14 @@ export interface SessionInfo {
   hasTrace: boolean;
   /** Whether archived (hidden from the default list, grouped under "Archived"). */
   archived: boolean;
+  /**
+   * Absolute path of the session's latest Trace file (the current context shard); absent
+   * when no Trace exists yet. Populated on the **single-session GET only** — list rows omit
+   * it (locating it costs a directory walk per Session). The web's `/model` switch puts it
+   * into the new session's `<model_switch_from>` block so the model can read the source
+   * history itself when it needs it.
+   */
+  tracePath?: string;
 }
 
 /**
@@ -562,6 +570,12 @@ export type TaskInputPart =
 
 export interface TaskCreateRequest {
   input: TaskInputPart[];
+  /**
+   * Thinking level for this Task's LLM requests (a per-turn parameter; one of
+   * `none | low | medium | high | xhigh`, anything else is a 400). Omitted = falls back to
+   * the session's default (the Agent config's `model.thinking_level`).
+   */
+  thinkingLevel?: ThinkingLevelName;
 }
 
 export interface TaskCreateResponse {