fix(queued-messages): clamp long queued messages to 3 lines

[harshjainnn]

Long queued messages (e.g. a pasted code block) previously rendered at full height, and this compounded with multiple queued messages, pushing the composer off-screen. Clamp to 3 lines with a fade mask and a 'Show more/less' toggle, mirroring the clamp pattern already used for sent messages in ChatThread's UserBubble.

Fixes #3150

Problem

Queued follow-up messages render at full height with no clamp. A long queued message (e.g. a pasted code block) can grow the dock to hundreds of pixels tall, and this compounds when multiple long messages are queued at once — pushing the composer off-screen.

Changes

Clamped QueuedMessageView content to 3 lines by default, with a bottom fade mask and a "Show more/less" toggle that only appears when the content actually overflows the clamp. This mirrors the existing clamp-by-measured-height pattern used in ChatThread.tsx's UserBubble for sent messages — a ResizeObserver compares scrollHeight against the clamped clientHeight, since overflow can't be determined from character count alone (it depends on wrap width).

Also changed the outer row's alignment from align="center" to align="start" so the icon and action buttons (Steer/Edit/Discard) stay pinned to the top when content spans multiple lines, instead of being vertically centered against a tall block.

How did you test this?

• Queued several short messages — dock renders unchanged, no toggle appears.
• Queued a message containing a long code block — content clamps to 3 lines with a fade, "Show more" expands it, "Show less" re-collapses it.
• Queued a mix of short and long messages together — short ones render untouched, long ones clamp independently of each other.

Automatic notifications

• Publish to changelog?
• Alert Sales and Marketing teams?

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[harshjainnn]

/trunk merge

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[greptile-apps]

_{Reviews (1): Last reviewed commit: "fix(queued-messages): clamp long queued ..." | Re-trigger Greptile}