fix: move tg_connect to general, rustfmt upstream, fix UpstreamManager::new tests

- Relocate tg_connect from [timeouts] to [general] with validation and docs updates.
- Apply rustfmt to per-attempt upstream connect timeout expression in upstream.rs.
- Pass tg_connect_timeout_secs in all UpstreamManager::new test call sites.
- Wire hot reload and runtime snapshot to general.tg_connect.

src/proxy/tests/client_more_advanced_tests.rs

@@ -100,6 +100,7 @@ async fn blackhat_proxy_protocol_massive_garbage_rejected_quickly() {
             1,
             1,
             1,
+            10,
             1,
             false,
             stats.clone(),
@@ -146,6 +147,7 @@ async fn edge_tls_body_immediate_eof_triggers_masking_and_bad_connect() {
             1,
             1,
             1,
+            10,
             1,
             false,
             stats.clone(),
@@ -195,6 +197,7 @@ async fn security_classic_mode_disabled_masks_valid_length_payload() {
             1,
             1,
             1,
+            10,
             1,
             false,
             stats.clone(),