Eliminate ESLint warnings and legacy overrides

What

Eliminate the nine remaining ESLint warnings and retire the narrow legacy-file overrides added in #1805 by modernizing the affected source files safely.

Why

The current gate passes, but warnings and per-file suppressions reduce signal and leave legacy equality, expression, JSDoc, and operator-precedence debt.

Tier

tier:standard — edits are bounded to named JavaScript files but some loose comparisons and expression statements require behavior-preserving decisions.

Files

• .eslintrc.js
• assets/js/activity-stream.js
• assets/js/command-palette.js
• assets/js/coupon-code.js
• assets/js/dashboard-statistics.js
• assets/js/dns-management.js
• assets/js/settings-loader.js
• assets/js/webhook-page.js
• Legacy override targets listed in .eslintrc.js

Reference pattern

Edit unminified source only, remove each override rule only after its target files pass, then regenerate minified assets with pnpm run build:dev.

Implementation steps

1. Resolve the nine warnings without changing runtime behavior.
2. Replace loose comparisons and ambiguous expressions in small reviewed batches.
3. Correct JSDoc and localized-global declarations at their source where practical.
4. Remove obsolete override entries and rebuild generated assets.

Acceptance criteria

• pnpm run lint:js reports zero errors and zero warnings.
• Legacy overrides are reduced or removed.
• No minified file is hand-edited.
• pnpm run build:dev and pnpm run quality pass.
• Relevant browser flows still work.

Verification

• pnpm run lint:js
• pnpm run build:dev
• pnpm run quality
• Browser smoke checks for affected admin and checkout flows

Dependency

Blocked by #1805; begin after PR #1806 merges.

aidevops.sh v3.32.317 plugin for OpenCode v1.18.29 with gpt-5.6-sol spent 4h 26m and 539,830 tokens on this with the user in an interactive session.

Begin after PR #1806 merges. Read .eslintrc.js and the listed assets/js files, then run pnpm run lint:js to identify the nine warnings and their legacy override targets. Update only unminified sources, remove overrides after their targets pass, run pnpm run build:dev and pnpm run quality, and verify the affected admin and checkout browser flows.