fix: Recent sort precision + search UX overhaul + devcontainer DX

[aniongithub]

A grab-bag of related fixes that came out of investigating the "Sort: Recent shows wrong order" bug, plus several search-UX improvements that surfaced while testing.

Wiki engine

Recent sort actually sorts by recency now (01855b5)

modified was stored via time.RFC3339 (second precision). Wiki-sync git pull writes batches of files within the same wall-clock second, so all rows ended up with an identical modified string → ORDER BY modified DESC had nothing to tiebreak on and SQLite returned them in arbitrary internal order. Most visibly: the "Sort: Recent" list in the web UI did not reflect recency.

• Switch to time.RFC3339Nano on both write paths so the filesystem's nanosecond mtime survives into the index.
• Add path ASC as a stable tiebreaker on the two queries that sort by modified.
• Parse with RFC3339Nano (backward-compatible with legacy seconds-only strings).
• Existing DBs self-migrate on next Open(): Reindex sees idxMtime != diskMtime and re-stores every row at ns precision.
• Regression test TestListPagesRecentSortDistinguishesSameSecondMtimes.

Web UI

Persistent search filter + clear button (626f2be)

• Lazy-initialize searchQuery from localStorage('mm-search-query') and persist on every keystroke, so filters survive a page reload.
• On first mount, if a saved query is present, restore the filtered list instead of falling back to all pages.
• Add a small × button rendered inside the search input when it's non-empty; clicking it clears the query and re-loads the full page list.

Search-match highlighting in the rendered page (e4a371c)

• Wrap each occurrence of every search token in <mark> in the rendered markdown, and scroll the first match into view.
• Operates on parsed DOM (DOMParser), not a regex over raw HTML, so tags / attributes / hrefs / mermaid placeholders are never touched.
• Skips <script> / <style> / existing <mark>. Code blocks still get highlighted (users searching for an identifier usually want to see it).
• useMemo keyed on [body, query, editing] keeps re-highlighting off the hot path.

Highlight matches in sidebar + page header (9176844)

Same <Highlighted> Preact component over a shared searchTokens/searchRegex pair, applied to:

• Sidebar page-list (title + path of every item)
• Page header (current page title + path subline)

Global mark { ... } CSS using var(--accent) blends with both themes.

Quoted phrase search + mermaid re-render (4e963c4)

• searchTokens now recognizes "quoted phrases" as a single token. The quoted text passes through verbatim to FTS5 (which natively interprets "phrase" as a phrase match) and highlights as one unit on the page. Bare unquoted words still tokenize individually.
• Interior whitespace in phrase tokens collapses to \s+, so "MCP server" still highlights when the rendered text has a newline or extra spaces.
• Mermaid render effect now depends on renderedBodyHTML instead of current. Previously, when searchQuery changed, the body's .mermaid divs were replaced by Preact but mermaid.run() never re-ran on the new nodes, leaving diagram source as raw text on the page.

Devcontainer DX (34a012a)

The browser launched from VS Code's Ports panel was opening http://[::1]:51888/ and getting "can't be reached":

• appPort: bind 127.0.0.1:51888->4242 explicitly instead of letting Docker dual-stack the host loopback. VS Code's port panel preferred [::1] on dual-stack hosts; the container only listens on IPv4, so that URL hung.
• launch.json: pass --addr 0.0.0.0:4242 to the dev-server launch configs. The serve default is 127.0.0.1:4242, which inside a container is unreachable from the Docker port-forward.
• launch.json: WebUI debug config now opens http://localhost:51888 (the forwarded host port), not :4242. Launched in the host's Chrome via browserLaunchLocation: "ui", so it must use the host-side port.

Backward compatibility

• No schema changes.
• Existing DBs self-heal on next Open() (ns-precision mtimes get re-stored as Reindex notices the mismatch).
• All existing tests pass; new regression tests for Recent sort included.