Description

Non-blocking Minors from the v1.1 whole-branch review. M1 (plan-mandated): scanFrontmatter/scanLine muted spans use th.Blockquote but tests assert th.Muted — equal in all 3 shipped themes today, fragile if a future theme diverges them. M2: cycleTheme stores preview style but doesn't re-Render an already-open preview pane until toggle. M3: picker textinput prompt/text not themed (bubbles default). M4: selected-row highlight covers label but not the '▸ ' pointer.

Acceptance Criteria

• #1 muted frontmatter spans painted with intended semantic color
• #2 open preview pane recolors on Ctrl+T
• #3 picker textinput uses theme colors