chore: drop the knip:fix PostToolUse hook

Auto-running `knip --fix` after every Edit/Write fights the agent
mid-change: an `export` added in one file is deleted as "exported but
nobody imports" before the `import` in the consuming file is written.

Knip is already enforced as a PR check (.github/workflows/knip.yml runs
`bun run knip` on every PR to main), which is the right place for it —
whole-repo validation once the change is complete, not after each edit.
`typecheck` and `lint:fix` stay; they are edit-local and idempotent.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

Author: davidsu

.claude/settings.json

@@ -18,10 +18,6 @@
           {
             "type": "command",
             "command": "bun run lint:fix 2>&1 | head -30"
-          },
-          {
-            "type": "command",
-            "command": "bun run knip:fix 2>&1 | head -50"
           }
         ]
       },
@@ -35,10 +31,6 @@
           {
             "type": "command",
             "command": "bun run lint:fix 2>&1 | head -30"
-          },
-          {
-            "type": "command",
-            "command": "bun run knip:fix 2>&1 | head -50"
           }
         ]
       }