fix(browser): dual transport — Unix socket + HTTP Docker + binary corruption detection

Root cause on macOS: camoufox-browser@0.1.0 downloads an alpha binary
(v150.0.2-alpha.26) from daijro/camoufox that has a broken macOS build
(missing libmozglue.dylib). Binary crashes with SIGABRT/SIGKILL.

Changes:
1. gyandoot-browser client now supports TWO transports:
   - Transport::UnixSocket (existing — daemon IPC)
   - Transport::Http (new — Docker REST API on port 9377)
2. init_browser() tries Docker HTTP first, falls back to npx daemon
3. HTTP transport maps browser actions to Docker REST endpoints
   (/navigate, /tabs, /health, etc.) with correct userId params
4. check_known_errors() detects libmozglue.dylib + SIGKILL patterns
5. Browser cache check works for both macOS and Linux paths
6. Error messages correctly say 'Use Docker' on corrupted binary
7. Added reqwest dep to gyandoot-agent for Docker health check

Clean build: 0 errors

crates/gyandoot-browser/Cargo.toml

@@ -3,7 +3,7 @@ name = "gyandoot-browser"
 version.workspace = true
 edition.workspace = true
 license.workspace = true
-description = "GyanDoot v2 — Camoufox browser automation via daemon IPC (Unix socket protocol)"
+description = "GyanDoot v2 — Camoufox browser automation via daemon IPC (Unix socket + HTTP fallback)"
 
 [dependencies]
 gyandoot-core = { path = "../gyandoot-core" }
@@ -15,4 +15,5 @@ anyhow.workspace = true
 tracing.workspace = true
 uuid.workspace = true
 chrono.workspace = true
-dirs.workspace = true
+dirs.workspace = true
+reqwest = { workspace = true, default-features = false, features = ["json"] }