fix(proxy): log when SOCKS5 credential auto-encoding rewrites URL (#157) (#209)

* fix(proxy): log when SOCKS5 credential auto-encoding rewrites URL (#157)

Auto URL-encoding of SOCKS5 credentials (added in v0.3.26 to fix Chromium's
'=' truncation bug) currently happens silently. Users debugging connectivity
have no way to know the wrapper rewrote their proxy URL — the original #157
thread took 8 round-trips to surface this exact ambiguity.

Emit a log when re-encoding actually changes the URL: INFO on Python's
'cloakbrowser' logger, console.debug in JavaScript. Stays silent on
already-encoded inputs and credential-less URLs to avoid false-positive
noise. Credentials are not included in the log message.

Tests: 3 new cases per language (Python caplog, JS vi.spyOn console.debug)
covering trigger / silent-when-encoded / silent-when-no-creds.

* fix(proxy): gate log on credential change, not full URL diff

Per Copilot review on #209: urlparse cosmetically lowercases scheme and
hostname, so comparing the full reconstructed URL to the input would emit
"Auto URL-encoded SOCKS5..." even for inputs like
`socks5://USER:pass@HOST.com:1080` where no credential encoding happened.

Compare raw vs encoded user/password substrings instead. Mirror the same
condition in JS for parity (JS's manual parser preserves case today, but the
credential-level compare is more robust against future changes).

Adds one regression test per language.

tests/test_proxy.py

@@ -284,6 +284,42 @@ class TestResolveProxyConfig:
         _, args = _resolve_proxy_config("socks5://user:pass%3D123@host:1080")
         assert args == ["--proxy-server=socks5://user:pass%3D123@host:1080"]
 
+    def test_socks5_string_logs_info_when_reencoding(self, caplog):
+        # When wrapper actually rewrites the URL (e.g. unencoded '=' in pwd),
+        # surface an INFO log so users debugging SOCKS5 connectivity (#157)
+        # can see what the wrapper did instead of being silently surprised.
+        import logging
+        with caplog.at_level(logging.INFO, logger="cloakbrowser"):
+            _resolve_proxy_config("socks5://user:pass=123@host:1080")
+        assert any("Auto URL-encoded SOCKS5" in r.message for r in caplog.records)
+        # Credentials must not leak into the log.
+        for r in caplog.records:
+            assert "pass=123" not in r.message
+            assert "pass%3D123" not in r.message
+
+    def test_socks5_string_silent_when_already_encoded(self, caplog):
+        # Idempotent path: pre-encoded URL produces no log noise.
+        import logging
+        with caplog.at_level(logging.INFO, logger="cloakbrowser"):
+            _resolve_proxy_config("socks5://user:pass%3D123@host:1080")
+        assert not any("Auto URL-encoded SOCKS5" in r.message for r in caplog.records)
+
+    def test_socks5_string_silent_when_no_credentials(self, caplog):
+        # No userinfo at all → no encoding work → no log.
+        import logging
+        with caplog.at_level(logging.INFO, logger="cloakbrowser"):
+            _resolve_proxy_config("socks5://host:1080")
+        assert not any("Auto URL-encoded SOCKS5" in r.message for r in caplog.records)
+
+    def test_socks5_string_silent_when_only_cosmetic_change(self, caplog):
+        # urlparse lowercases scheme and hostname, but credentials are
+        # untouched. The log must NOT fire for these cosmetic-only rewrites
+        # (regression for Copilot's review on PR #209).
+        import logging
+        with caplog.at_level(logging.INFO, logger="cloakbrowser"):
+            _resolve_proxy_config("socks5://USER:pass@HOST.com:1080")
+        assert not any("Auto URL-encoded SOCKS5" in r.message for r in caplog.records)
+
     def test_socks5_string_no_creds_unchanged(self):
         _, args = _resolve_proxy_config("socks5://host:1080")
         assert args == ["--proxy-server=socks5://host:1080"]