Readout 3.0.0

3.0.0

Focus on what's new: filter the document to unread changes, see reading
cost at a glance, link straight to a section, and resume where you left off
even after heavy agent rewrites.

Show Only Changes (⇧⌘K). A View menu toggle (and toolbar-adjacent
keyboard shortcut) hides every block already read; headings stay visible as
context. The rail, N/⇧N jumps, and the "All caught up" empty state all
respect the filter, and silent re-renders (checkbox toggles, CJK class
changes) no longer disturb it. Covered by patch-engine tests (filter, link
button, silent re-render, restore).

Word count and reading time. The window subtitle shows
"1,234 words · 3 min read" when a document has no task list (CJK characters
count individually, Latin text counts words), mirrored in the sidebar
footer. New ReadingStats core unit with tests.

Section links. Hovering a heading reveals a § button that copies a
filename#anchor link to the clipboard (native copyLink message path,
localized tooltip).

Recent files on welcome. The welcome window lists the five most recent
Markdown files with icons and parent-folder hints for one-click reopening
(existing files only).

Excerpt-anchored resume. The saved reading position now stores the top
block's first 120 characters alongside the baseline; on reopen the excerpt
is matched first (prefix, then containment, then half-excerpt fallbacks via
new ExcerptAnchor core unit), with the legacy block index as fallback for
older records. Scroll-only saves still skip unchanged baselines.

Docs. docs/design.md documents the focus-and-resume behavior; README
(EN + zh-CN) gains the new capabilities and shortcut. Chinese localization
at 100% for the new strings.

Ad-hoc signature (no Developer ID): first launch needs
System Settings → Privacy & Security → Open Anyway, as before.