[triprjt]

What & why

Adds arbitrary text sizing to the board instead of limiting users to S/M/L/XL:

• adds a numeric pixel-size input beside the existing presets
• preserves explicit sizes throughout board style types, markdown rendering, and textarea editing
• accepts and measures numeric font sizes in the backend
• works with the companion canvas-harness change so corner-dragging standalone text scales the font proportionally, similar to Excalidraw

This addresses #350.

Companion dependency PR: winlp4ever/canvas-harness#46

This PR is intentionally a draft until the companion library change is merged and released, at which point the @canvas-harness/* dependency can be updated to that release.

Related issue

Closes #350

How was it tested?

• added backend coverage for measuring text at an explicit 72 px font size
• verified numeric font-size editing and proportional corner-resize behavior in a self-hosted Dim0 deployment
• verified existing preset sizes continue to render and edit normally

Checklist

• Branched off main
• PR title follows Conventional Commits (type(scope): message)
• Ran the app locally and confirmed the change works
• Change is focused on one thing
• Updated docs/comments if behavior changed

[winlp4ever]

nice, this follows the plan 👍 I know it's blocked on canvas-harness#46, and the NaN/tsc errors on the branch should go away once that's released. some things to sort out in the meantime:

1. validate on the backend. font_size: FontSize | float accepts 0, negatives and inf, and inf crashes the agent layout (ceil(inf)). use a constrained float (8–256), same range as the harness.
2. don't save on every keystroke. typing "24" applies 2px first, then 24, which means two undo entries + two sync ops and the text collapses for a moment. commit on blur/enter instead, and add min/max on the input.
3. old clients. desktop builds and cached PWAs on harness 0.2.0 will render numeric sizes as NaN, and their auto-fit can sync h: null back. we need a plan here, e.g. a min client version check, or not writing numbers until the bump has been out for a release or two. happy to talk through it.
4. drop the canvas-lite-markdown.tsx changes. nothing imports that file anymore, the harness does the real rendering, so those changes don't do anything.
5. one line-height ratio. use the harness resolver on the frontend instead of re-deriving * 1.25, and in text_measure.py add a comment pointing at the harness constant so they don't drift.
6. docstrings on getLineHeightPx, getMarkdownLineHeightPx and fontSizeToTwClass (repo rule in AGENTS.md).

once #46 is out, bump @canvas-harness/* here and I'll do another pass

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

📢 Thoughts on this report? Let us know!

[triprjt]

Addressed the actionable review items in 921c35d:

• Backend explicit font sizes are now finite and constrained to 8–256, for both Style and LinkStyle, with validation tests for lower/upper bounds, out-of-range values, and NaN/infinity.
• Text measurement now clamps/falls back defensively, preserves preset line heights when a numeric value exactly matches a preset, and uses a named NUMERIC_LINE_HEIGHT_RATIO aligned with canvas-harness.
• The font-size field now keeps a local draft and commits only on blur or Enter. It rounds/clamps to 8–256, restores the current value when left empty, and has focused interaction tests.
• Removed the unrelated/dead canvas-lite-markdown.tsx changes from the combined PR diff.
• Kept frontend conversion through the canvas-harness resolver and added the requested documentation.

The package bump is still intentionally pending merge and release of canvas-harness PR #46. Until that release exists, this Dim0 PR should remain a draft; local type-check validation used the built artifacts from #46 without committing vendored output or dependency changes.