feat(hooks): config-protection PreToolUse guards quality-gate files

Blocks Edit/Write to guardrails (settings.json + .claude/settings*, lib/gitflow.sh, .githooks/*, doctor.sh, hooks/*.sh self-guard, lib/tests/*, lint) so a gate can't be weakened to pass an error. Bypass = one-shot sentinel .claude/.config-edit-ok (non-empty reason, logged+consumed), not an env-var. Adaptation from the ECC second-look (BDR-047 corrob): own bash idiom, not ECC's Node dispatcher. shellcheck clean, test 20/20.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XpphkdTosUzokBDNG7PToS

settings.json

@@ -245,6 +245,16 @@
             "command": "bash ~/.claude/hooks/rtk-rewrite.sh"
           }
         ]
+      },
+      {
+        "matcher": "Edit|Write|MultiEdit",
+        "hooks": [
+          {
+            "type": "command",
+            "command": "bash ~/.claude/hooks/config-protection.sh",
+            "timeout": 5
+          }
+        ]
       }
     ],
     "UserPromptSubmit": [