[Task] Audit and align chrome/sidebar icon size and stroke consistency

[Astro-Han]

Goal

Chrome/sidebar icons should feel visually consistent at the sizes where PawWork actually uses them, especially 16px dense sidebar rows and 20px controls.

The immediate known issue is new-session: it has a similar rendered bounding box to neighboring sidebar icons, but reads noticeably thinner because its traced outline has lower visual density.

Scope

In scope:

• Audit common chrome/sidebar icons, including at least new-session, magnifying-glass, settings-gear, dot-grid, sort, schedule, edit, archive, branch, file-tree, folder, and folder-open.
• Classify icon sources: hand-authored or near-20-unit path vs imagegen/potrace fill path.
• Compare effective rendered bbox, wall thickness, internal whitespace, and perceived density at 16px and 20px.
• Fix confirmed visual outliers, starting with new-session.
• Attach or link a real icon.tsx comparison page in the PR for review.

Out of scope:

• Redesigning the full icon family from scratch.
• Changing icons unrelated to chrome/sidebar usage unless the audit shows the same issue.
• Bundling this into feature PRs such as feat(sidebar): project rename and remove from sidebar #517.
• Deciding the long-term hand-authored vs bitmap-trace strategy for all icons.

Relevant files or context

Likely files:

• packages/ui/src/components/icon.tsx
• packages/app/src/pages/layout/pawwork-sidebar.tsx
• packages/app/src/components/titlebar.tsx
• packages/app/src/components/settings-page.tsx

Context:

• This was discovered during PR feat(sidebar): project rename and remove from sidebar #517 while replacing the project-group chevron with folder / folder-open.
• folder / folder-open were adjusted separately and should stay in feat(sidebar): project rename and remove from sidebar #517 scope.
• new-session appears visually thin next to search/settings/sidebar controls, despite a roughly matching 17-18px bbox.

Verification

• Build or attach a real icon.tsx comparison page showing the audited icons at 16px and 20px.
• Verify new-session no longer reads thinner than adjacent sidebar icons.
• Verify the sidebar still looks balanced in Electron.
• Run the targeted UI/package typecheck touched by the change.

Execution mode

Agent should investigate and propose a plan first.

[Astro-Han]

Latest verification on 6501ab650: leaving this open.

This is still an audit task, not something I can verify-close from a single smoke pass.

I re-checked the current umbrella/rewrite tracking and do not see a safe reason to mark this as subsumed:

• [Feature] Rewrite packages/ui + packages/app visual layer against PawWork design system (incremental PR series) #440 slice 08 already landed the chrome icon registry redraw,
• but this issue asks for a broader follow-up audit across multiple sidebar/chrome icons, density comparison at 16px/20px, and a real comparison page for review.

So I am leaving #523 open as its own audit/fix pass.