feat(tools): add web_search_tool for internet search

Add native web search capability that works regardless of LLM tool-calling
support. This is particularly useful for GLM models via Z.AI that don't
reliably support standard tool calling formats.

Features:
- DuckDuckGo provider (free, no API key required)
- Brave Search provider (optional, requires API key)
- Configurable max results and timeout
- Enabled by default

Configuration (config.toml):
  [web_search]
  enabled = true
  provider = "duckduckgo"
  max_results = 5

The tool allows agents to search the web for current information without
requiring proper tool calling support from the LLM.

Also includes CI workflow fix for first-interaction action inputs.

Cargo.lock

@@ -4410,6 +4410,12 @@ dependencies = [
  "serde_derive",
 ]
 
+[[package]]
+name = "urlencoding"
+version = "2.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "daf8dba3b7eb870caf1ddeed7bc9d2a049f3cfdfae7cb521b087cc33ae4c49da"
+
 [[package]]
 name = "utf-8"
 version = "0.7.6"
@@ -5225,6 +5231,7 @@ dependencies = [
  "tower-http",
  "tracing",
  "tracing-subscriber",
+ "urlencoding",
  "uuid",
  "webpki-roots 1.0.6",
 ]