feat(web): add Parallel as alternative web search/extract backend (#1696)

* feat(web): add Parallel as alternative web search/extract backend

Adds Parallel (parallel.ai) as a drop-in alternative to Firecrawl for
web_search and web_extract tools using the official parallel-web SDK.

- Backend selection via WEB_SEARCH_BACKEND env var (auto/parallel/firecrawl)
- Auto mode prefers Firecrawl when both keys present; Parallel when sole backend
- web_crawl remains Firecrawl-only with clear error when unavailable
- Lazy SDK imports, interrupt support, singleton clients
- 16 new unit tests for backend selection and client config

Co-authored-by: s-jag <s-jag@users.noreply.github.com>

* fix: add PARALLEL_API_KEY to config registry and fix web_crawl policy tests

Follow-up for Parallel backend integration:
- Add PARALLEL_API_KEY to OPTIONAL_ENV_VARS (hermes doctor, env blocklist)
- Add to set_config_value api_keys list (hermes config set)
- Add to doctor keys display
- Fix 2 web_crawl policy tests that didn't set FIRECRAWL_API_KEY
  (needed now that web_crawl has a Firecrawl availability guard)

* refactor: explicit backend selection via hermes tools, not auto-detect

Replace the auto-detect backend selection with explicit user choice:
- hermes tools saves WEB_SEARCH_BACKEND to .env when user picks a provider
- _get_backend() reads the explicit choice first
- Fallback only for manual/legacy config (uses whichever key is present)
- _is_provider_active() shows [active] for the selected web backend
- Updated tests, docs, and .env.example to remove 'auto' mode language

* refactor: use config.yaml for web backend, not env var

Match the TTS/browser pattern — web.backend is stored in config.yaml
(set by hermes tools), not as a WEB_SEARCH_BACKEND env var.

- _load_web_config() reads web: section from config.yaml
- _get_backend() reads web.backend from config, falls back to key detection
- _configure_provider() saves to config dict (saved to config.yaml)
- _is_provider_active() reads from config dict
- Removed WEB_SEARCH_BACKEND from .env.example, set_config_value, docs
- Updated all tests to mock _load_web_config instead of env vars

---------

Co-authored-by: s-jag <s-jag@users.noreply.github.com>

tests/integration/test_web_tools.py

@@ -3,7 +3,7 @@
 Comprehensive Test Suite for Web Tools Module
 
 This script tests all web tools functionality to ensure they work correctly.
-Run this after any updates to the web_tools.py module or Firecrawl library.
+Run this after any updates to the web_tools.py module or backend libraries.
 
 Usage:
     python test_web_tools.py              # Run all tests
@@ -11,7 +11,7 @@ Usage:
     python test_web_tools.py --verbose    # Show detailed output
 
 Requirements:
-    - FIRECRAWL_API_KEY environment variable must be set
+    - PARALLEL_API_KEY or FIRECRAWL_API_KEY environment variable must be set
     - An auxiliary LLM provider (OPENROUTER_API_KEY or Nous Portal auth) (optional, for LLM tests)
 """
 
@@ -28,12 +28,14 @@ from typing import List
 
 # Import the web tools to test (updated path after moving tools/)
 from tools.web_tools import (
-    web_search_tool, 
-    web_extract_tool, 
+    web_search_tool,
+    web_extract_tool,
     web_crawl_tool,
     check_firecrawl_api_key,
+    check_web_api_key,
     check_auxiliary_model,
-    get_debug_session_info
+    get_debug_session_info,
+    _get_backend,
 )
 
 
@@ -121,12 +123,13 @@ class WebToolsTester:
         """Test environment setup and API keys"""
         print_section("Environment Check")
         
-        # Check Firecrawl API key
-        if not check_firecrawl_api_key():
-            self.log_result("Firecrawl API Key", "failed", "FIRECRAWL_API_KEY not set")
+        # Check web backend API key (Parallel or Firecrawl)
+        if not check_web_api_key():
+            self.log_result("Web Backend API Key", "failed", "PARALLEL_API_KEY or FIRECRAWL_API_KEY not set")
             return False
         else:
-            self.log_result("Firecrawl API Key", "passed", "Found")
+            backend = _get_backend()
+            self.log_result("Web Backend API Key", "passed", f"Using {backend} backend")
         
         # Check auxiliary LLM provider (optional)
         if not check_auxiliary_model():
@@ -578,7 +581,9 @@ class WebToolsTester:
             },
             "results": self.test_results,
             "environment": {
+                "web_backend": _get_backend() if check_web_api_key() else None,
                 "firecrawl_api_key": check_firecrawl_api_key(),
+                "parallel_api_key": bool(os.getenv("PARALLEL_API_KEY")),
                 "auxiliary_model": check_auxiliary_model(),
                 "debug_mode": get_debug_session_info()["enabled"]
             }