fix(next): let composer content follow the chat font size

Merged
TE
8d ago
+218-50

Changing Chat Display’s font size now scales the composer’s text, headings and code, New Tab and shell prompts, queued prompts and their editors, and transcript headings and tables. These surfaces previously used fixed type sizes while the conversation body followed the setting.

Leo, word for word: "leo make sure font size everywhere (like text input area) is customizable".

Audit: fixed the rich-text draft and placeholder; inline/fenced code and draft headings; the legacy prompt and New Tab fields; the live New Tab agent, shell and console fields; chat shell mode; queued prompt text and editing; and transcript headings/tables. The regular transcript body, transcript code, and sent-message editor already follow the chat setting. Cmd +/− already changes agentPane.zoom through native whole-pane zoom and scales all webview text, including chrome; that path stays intact. Native Interface Size propagation is separate work in #25703.

Composer controls follow the last content line as its height changes, and the minimum composer height and editor caps scale with that line height. Risk: this changes editor geometry at large text sizes; the browser regression exercises 14, 21 and 28px in both themes and chat, new-chat and real New Tab contexts, plus shell and queued editing.

Gallery: agent-pane.composer/font-size-{chat,new-chat,new-tab}-{14,21,28}.

Validation: 40648556110 at fa4324dc7543ce4d2a3d9d50714cc787536f97f8 passes all 7 browser tests (86 assertions) and the full webview check: formatting, lint, types, static gates and protocol codegen. 40647875413 proves all 7 font cases fail on the base, and all 4 existing alignment tests pass on the identical product source. The test cycles 21 → 14 → 28px; shell mode uses the editor's supported typing API, waits for the shell field to be visible, then checks its computed font size. No sleeps. Design-token/type-scale baselines shrink. No new timer or observer; no native source change or app compile.

No capture: No native app tour was run because this changes webview typography only, with no native source or glass material changes. The real composer and New Tab gallery captures below exercise all changed text contexts in light and dark.

Generated gallery captures at base 0c8336391b32df85bcdd7db7eac2f3f0f82a54d8 and product head 4eb0aca6c57d21ce88c80302cd8605e5315fe544 (product/gallery source unchanged at fa4324dc7543ce4d2a3d9d50714cc787536f97f8).

Chat

SizeLight beforeLight afterDark beforeDark after
14pxchat light 14px basechat light 14px headchat dark 14px basechat dark 14px head
21pxchat light 21px basechat light 21px headchat dark 21px basechat dark 21px head
28pxchat light 28px basechat light 28px headchat dark 28px basechat dark 28px head

New Chat

SizeLight beforeLight afterDark beforeDark after
14pxnew-chat light 14px basenew-chat light 14px headnew-chat dark 14px basenew-chat dark 14px head
21pxnew-chat light 21px basenew-chat light 21px headnew-chat dark 21px basenew-chat dark 21px head
28pxnew-chat light 28px basenew-chat light 28px headnew-chat dark 28px basenew-chat dark 28px head

New Tab

SizeLight beforeLight afterDark beforeDark after
14pxnew-tab light 14px basenew-tab light 14px headnew-tab dark 14px basenew-tab dark 14px head
21pxnew-tab light 21px basenew-tab light 21px headnew-tab dark 21px basenew-tab dark 21px head
28pxnew-tab light 28px basenew-tab light 28px headnew-tab dark 28px basenew-tab dark 28px head

Independent Astra review at fa4324dc7543ce4d2a3d9d50714cc787536f97f8 is pending.

Changelog

Fixed: Composer input, New Tab, shell and queued prompts, and Markdown headings and tables follow the chat font size.

Agent session: agent session