Fix Lint

Run `npm run lint` and fix every reported error and warning, then commit the fixes.

## Steps

### 1. Run lint and capture output

```bash
npm run lint 2>&1

If lint exits 0 with no output, report "No lint issues found" and stop — do not create an empty commit.

2. Fix all reported issues

Work through each file that has errors or warnings. Read each file before editing it.

Common patterns and how to fix them:

react/jsx-no-comment-textnodes — A string like // FOO appears as raw text inside JSX. → Wrap it: {'// FOO'}

@typescript-eslint/no-unused-vars — A variable, function, or import is declared but never used. → Remove the declaration entirely. Do not prefix with _ unless the variable is a required destructuring placeholder.

react-hooks/set-state-in-effect — setState called directly inside a useEffect body. → If the effect is resetting state in response to a user action (e.g. a search input change), move the reset into the event handler that triggers the state change instead of using an effect. If the effect is accumulating time-series data (e.g. history/sparkline buffers that must update on every tick), keep the pattern and add // eslint-disable-next-line react-hooks/set-state-in-effect on the line before the setState call — this is a legitimate exception.

react-hooks/refs — ref.current is read or written during render (outside of effects or event handlers). → Move the mutation into a useEffect. Return a state value instead of the ref directly.

react/jsx-no-useless-fragment — An unnecessary <>...</> wrapper. → Remove the fragment; return the child directly.

@typescript-eslint/no-explicit-any — any used in a type annotation. → Replace with the narrowest correct type. If the correct type is genuinely unknown at that boundary, use unknown instead of any.

3. Verify

npm run lint 2>&1

If new errors appear (introduced by your edits), fix them too. Repeat until lint exits cleanly.

4. Commit

Stage only the files you changed (never git add -A):

git add <file1> <file2> ...

Use a commit message that:

• Starts with Fix:
• Lists each file and what was fixed, grouped by rule
• Ends with the standard Co-Authored-By trailer

Example:

Fix: resolve ESLint errors and warnings

- page.tsx: replace setState-in-effect with event handler; wrap decorative // text in JSX expressions
- FooNode.tsx: remove unused fmtNum helper
- BarFields.tsx: remove unused getLabel function
- ArcGauge.tsx: remove unused startAngle/endAngle variables

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Pass the message via HEREDOC to preserve formatting:

git commit -m "$(cat <<'EOF'
Fix: ...

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
EOF
)"