web(review): confidence-aware date guesser with combined filename + path signals

Refactor suggestDateFromPath to combine multiple signals instead of
trying patterns in priority order:

- Filename Y-M-D corroborated by path Y-M/Y-M-D → HIGH (filename-
  agrees-path). Fixes the case where a Samsung-style 20240226_xxx.jpg
  under 2024/02/ was returning the path-only 2024-02-01.
- Filename Y-M-D with no path signal → HIGH (filename-only).
- 10/13-digit Unix epoch in basename → HIGH (unix-timestamp) —
  covers WeChat (mmexport...) and FB saves.
- Path Y-M-D → HIGH (path-ymd).
- Path Y-M only → MEDIUM (path-ym-default-day, synthesised day=01).
  Sidebar row labels these "(estimated day)" so the user knows.

Filename parser now accepts `.` and space separators (covers macOS
screenshots, manual 2024.02.26 renames). Path parser accepts `.` too.
OriginalName participates as a secondary filename signal when present
and different from the on-disk basename.

Patterns we explicitly DO NOT parse, to avoid silent date flips:
DD-MM-YYYY / MM-DD-YYYY, 2-digit years, bare camera sequence numbers.

Add photoNameAndDir(p) helper next to primaryFile so RightSidebar,
BulkActionBar, photoActions, and gridKeyNav all derive {fileName,
path} the same way — fixes the bug where photo.FileName was
undefined on the single-photo detail endpoint and the basename branch
was being skipped entirely.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

web/src/lib/actions/gridKeyNav.ts

@@ -12,6 +12,7 @@ import {
 } from '$lib/services/photoprism';
 import { acceptDateAndKeep, cachedPhoto } from '$lib/services/photoActions';
 import { suggestDateFromPath } from '$lib/utils/suggestDateFromPath';
+import { photoNameAndDir } from '$lib/types/photoprism';
 import { queryClient } from '$lib/queryClient';
 import { filters } from '$lib/stores/filters.svelte';
 import {
@@ -486,7 +487,10 @@ export function gridKeyNav(node: HTMLElement, params: GridKeyNavParams = {}) {
 					for (const id of ids) {
 						const p = cachedPhoto(id);
 						if (!p) return;
-						if (!suggestDateFromPath({ fileName: p.FileName, path: p.Path })) return;
+						const { fileName, path } = photoNameAndDir(p);
+						if (!suggestDateFromPath({ fileName, originalName: p.OriginalName, path })) {
+							return;
+						}
 					}
 					e.preventDefault();
 					void acceptDateAndKeep(ids);