fix(aux): add session_search extra_body and concurrency controls

Adds auxiliary.<task>.extra_body config passthrough so reasoning-heavy
OpenAI-compatible providers can receive provider-specific request fields
(e.g. enable_thinking: false on GLM) on auxiliary calls, and bounds
session_search summary fan-out with auxiliary.session_search.max_concurrency
(default 3, clamped 1-5) to avoid 429 bursts on small providers.

- agent/auxiliary_client.py: extract _get_auxiliary_task_config helper,
  add _get_task_extra_body, merge config+explicit extra_body with explicit winning
- hermes_cli/config.py: extra_body defaults on all aux tasks +
  session_search.max_concurrency; _config_version 19 -> 20
- tools/session_search_tool.py: semaphore around _summarize_all gather
- tests: coverage in test_auxiliary_client, test_session_search, test_aux_config
- docs: user-guide/configuration.md + fallback-providers.md

Co-authored-by: Teknium <teknium@nousresearch.com>

hermes_cli/config.py

@@ -487,6 +487,7 @@ DEFAULT_CONFIG = {
             "base_url": "",        # direct OpenAI-compatible endpoint (takes precedence over provider)
             "api_key": "",         # API key for base_url (falls back to OPENAI_API_KEY)
             "timeout": 120,        # seconds — LLM API call timeout; vision payloads need generous timeout
+            "extra_body": {},      # OpenAI-compatible provider-specific request fields
             "download_timeout": 30,  # seconds — image HTTP download timeout; increase for slow connections
         },
         "web_extract": {
@@ -495,6 +496,7 @@ DEFAULT_CONFIG = {
             "base_url": "",
             "api_key": "",
             "timeout": 360,        # seconds (6min) — per-attempt LLM summarization timeout; increase for slow local models
+            "extra_body": {},
         },
         "compression": {
             "provider": "auto",
@@ -502,6 +504,7 @@ DEFAULT_CONFIG = {
             "base_url": "",
             "api_key": "",
             "timeout": 120,        # seconds — compression summarises large contexts; increase for local models
+            "extra_body": {},
         },
         "session_search": {
             "provider": "auto",
@@ -509,6 +512,8 @@ DEFAULT_CONFIG = {
             "base_url": "",
             "api_key": "",
             "timeout": 30,
+            "extra_body": {},
+            "max_concurrency": 3,  # Clamp parallel summaries to avoid request-burst 429s on small providers
         },
         "skills_hub": {
             "provider": "auto",
@@ -516,6 +521,7 @@ DEFAULT_CONFIG = {
             "base_url": "",
             "api_key": "",
             "timeout": 30,
+            "extra_body": {},
         },
         "approval": {
             "provider": "auto",
@@ -523,6 +529,7 @@ DEFAULT_CONFIG = {
             "base_url": "",
             "api_key": "",
             "timeout": 30,
+            "extra_body": {},
         },
         "mcp": {
             "provider": "auto",
@@ -530,6 +537,7 @@ DEFAULT_CONFIG = {
             "base_url": "",
             "api_key": "",
             "timeout": 30,
+            "extra_body": {},
         },
         "flush_memories": {
             "provider": "auto",
@@ -537,6 +545,7 @@ DEFAULT_CONFIG = {
             "base_url": "",
             "api_key": "",
             "timeout": 30,
+            "extra_body": {},
         },
         "title_generation": {
             "provider": "auto",
@@ -544,6 +553,7 @@ DEFAULT_CONFIG = {
             "base_url": "",
             "api_key": "",
             "timeout": 30,
+            "extra_body": {},
         },
     },
     
@@ -812,7 +822,7 @@ DEFAULT_CONFIG = {
     },
 
     # Config schema version - bump this when adding new required fields
-    "_config_version": 19,
+    "_config_version": 20,
 }
 
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