feat: add persistent multi-model workers and orchestration budgets

include/cst_agent.h

@@ -111,6 +111,13 @@ typedef struct {
   char tools_off[1024]; /* ",name,name," tools switched off (/tools off) */
   /* Sub-agents (task tool). */
   int depth;              /* 0 = top-level; sub-agents run at 1 */
+  int orchestrate;        /* coordinator delegates write/shell work */
+  int orchestrate_override; /* CLI: 1 force on, -1 force off */
+  int subagent_steps, subagent_tasks, subagent_total;
+  void *worker_budget;    /* owned by the top-level agent */
+  int (*request_gate)(void *); /* reserve budget before each HTTP attempt */
+  void *request_gate_ud;
+  char cache_namespace[128];
   int read_only;          /* no write / shell tools */
   char tools_only[1024];  /* ",a,b," allowlist; empty = every tool */
   const char *role_prompt; /* role instructions (not owned) */
@@ -267,6 +274,7 @@ typedef struct {
   long http_status;
   char finish_reason[32];
   long prompt_tokens;
+  int cache_reported;
   long completion_tokens;
   long cached_tokens;      /* prompt tokens read from the provider's cache */
   long cache_miss_tokens;  /* prompt tokens billed at the full input price */
@@ -283,6 +291,8 @@ typedef struct {
   const char *api_key;
   const char *model;
   const char *reasoning_effort; /* NULL = not sent */
+  int (*request_gate)(void *);
+  void *request_gate_ud;
   const cst_message_t *msgs;
   int nmsgs;
   cst_llm_on_delta_fn on_delta;
@@ -433,6 +443,7 @@ long cst_agent_last_prompt_tokens(const cst_agent_t *a);
 /* Token use since the session was opened, and of the latest turn. */
 typedef struct {
   int requests;
+  int cache_known_requests;
   long prompt, cached, miss, write, out;
   double cost;      /* in currency; valid when priced */
   int priced;       /* every request had a known price */

include/cst_subagent.h

@@ -3,18 +3,20 @@
 
 /*
  * Sub-agents: the task(description, prompt, agent?) tool runs one turn of a
- * child agent with its own context and returns its final report.
+ * child agent with its own context and returns its final report and worker_id.
+ * Pass worker_id on subsequent calls to continue the persisted context.
  *
  * Roles: built-in general / explore / plan, plus Markdown files in
  * <ws>/.agent/agents/ and <config>/agents/ (the workspace wins, both win
  * over built-ins). Frontmatter: name, description, model, tools (allowlist),
- * max_steps, readonly; the body is the role's instructions.
+ * profile, max_steps, readonly; the body is the role's instructions.
  *
  * Transcripts: <ws>/.agent/sessions/<parent-id>/sub-<n>.jsonl, with a
  * sub-<n>.json summary next to each (not listed as sessions).
  */
 
 #include <stddef.h>
+#include "cst_agent.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -27,6 +29,7 @@ typedef struct {
   char desc[256];
   char source[16]; /* "builtin" | "workspace" | "user" */
   char model[128]; /* empty = the parent's */
+  char profile[64];
   char tools[1024]; /* ",a,b," allowlist; empty = all but task */
   int max_steps;    /* 0 = default */
   int read_only;
@@ -46,11 +49,30 @@ typedef struct {
   char role[64];
   char desc[160];
   char status[32]; /* "done" | "error" | "cancelled" | "running" */
+  char provider[32], model[128];
+  int requests, max_steps;
+  long prompt_tokens, cached_tokens, cache_write_tokens, output_tokens;
+  int priced;
+  int cache_known;
+  double cost;
+  char currency[8];
   int steps, tools;
   double ms;
   long long mtime;
 } cst_subagent_rec_t;
 
+void *cst_worker_budget_new(void);
+void cst_worker_budget_free(void *budget);
+void cst_worker_budget_reset(void *budget);
+char *cst_workers_budget_json(const cst_agent_config_t *cfg);
+/* Validated JSON configuration, stored in <workspace>/.agent/workers.json. */
+char *cst_workers_config_get(const char *workspace);
+int cst_workers_config_set(const char *workspace, const char *json,
+                           char *err, size_t err_sz);
+void cst_workers_config_apply(cst_agent_config_t *cfg);
+int cst_worker_cancel(const char *workspace, const char *parent_id,
+                      const char *worker_id);
+
 /* This parent session's sub-agent runs, newest first. */
 int cst_subagent_list(const char *workspace, const char *parent_id,
                       cst_subagent_rec_t *out, int max);