clarify thm-deriv-lincom

[d-morrison]

• does dx/dbeta need to be 0 for the result to hold?
• also, the dot products should be wrapped in parentheses, so the order of operations is unambiguous.
• also the comment about transposing the coefficient isn't relevant for the current theorem claim; add a separate corollary for transpose product and move the comment to that corollary
• the LHS of the current proof switches to transpose product notation; switch it to dot-product to be consistent

[d-morrison]

@claude

[github-actions]

👀 Picked up by workflow run #26651425611. R/Quarto/renv setup runs first (~3-5 min); Claude itself responds after that.

[claude]

I analyzed issue 840 and identified the four changes needed in _subfiles/math-prereqs/_sec_vector_calc.qmd. However, I cannot apply them automatically because Edit and Write permissions are not configured in .claude/settings.json. To enable automatic file editing for future runs, add "Edit()" and "Write()" to the allow array in .claude/settings.json.

[github-actions]

Pushed Claude's commits to claude/issue-840-20260529-171751 and opened draft PR: #842

[d-morrison]

Claude Code CLI (local session) is working on the linked PR #842 — paws off until I'm done.