dev/e2e: wall_clock regression check + deterministic fixture dates

`e2e.sh check` compares every indexed fixture's manifest wall clock with
the `wall_clock` reported by /image/metadata, /memories and
/photos/gps-summary; any disagreement fails.

- Fixture videos are stamped like phone containers: the America/New_York
  wall as a UTC creation_time (the label previously showed the UTC time).
- mtimes are pinned in America/New_York instead of the host's zone.
- The e2e env sets TZ=America/New_York (the #120 preflight): the Windows
  exe has no /etc/timezone, so server_zone() was otherwise None.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

dev/e2e/gen_fixtures.py

@@ -28,6 +28,7 @@ import sys
 from concurrent.futures import ThreadPoolExecutor
 from dataclasses import dataclass, field
 from pathlib import Path
+from zoneinfo import ZoneInfo
 
 FFMPEG = shutil.which("ffmpeg.exe") or shutil.which("ffmpeg")
 EXIFTOOL = shutil.which("exiftool.exe") or shutil.which("exiftool")
@@ -35,6 +36,10 @@ EXIFTOOL = shutil.which("exiftool.exe") or shutil.which("exiftool")
 # the drive letter must be escaped inside a filter argument.
 FONT = "C\\:/Windows/Fonts/consola.ttf"
 
+# The owner's display zone and the server zone the e2e env pins (TZ=...).
+# Naive fixture datetimes without GPS are walls in this zone.
+HOME_TZ = ZoneInfo("America/New_York")
+
 PLACES = {
     "santa_monica": (34.0100, -118.4960),
     "paris": (48.8584, 2.2945),
@@ -53,7 +58,9 @@ class Item:
     rel: str  # path relative to the library root, forward slashes
     kind: str  # "image" | "video"
     size: tuple[int, int] = (1600, 1200)
-    taken: dt.datetime | None = None  # written to EXIF / video creation_time
+    # Capture wall clock: EXIF DateTimeOriginal as-is; for videos, the wall in
+    # HOME_TZ, stamped as UTC creation_time the way phones write containers.
+    taken: dt.datetime | None = None
     gps: str | None = None  # key into PLACES
     camera: tuple[str, str] | None = None  # (Make, Model)
     mtime: dt.datetime | None = None  # pinned file mtime (undated fallback)
@@ -160,6 +167,21 @@ def build_items(today: dt.date) -> list[Item]:
     return items
 
 
+def expected_wall_clock(it: Item) -> str:
+    """The wall clock the server should report (`wall_clock`): the filename
+    date for the filename class (it outranks EXIF), else the capture wall,
+    else the pinned mtime rendered in HOME_TZ."""
+    import re
+    name = it.rel.rsplit("/", 1)[-1]
+    m = (re.search(r"(\d{4})(\d{2})(\d{2})[_-](\d{2})(\d{2})(\d{2})", name)
+         or re.search(r"(\d{4})-(\d{2})-(\d{2})_(\d{2})-(\d{2})-(\d{2})", name))
+    if m:
+        wall = dt.datetime(*map(int, m.groups()))
+    else:
+        wall = it.taken or it.mtime or dt.datetime(2024, 1, 1)
+    return wall.strftime("%Y-%m-%dT%H:%M:%S")
+
+
 def _same_day(today: dt.date, year: int, hour: int) -> dt.datetime:
     # Feb 29 in a non-leap year would be invalid; fall back to Feb 28.
     try:
@@ -200,7 +222,8 @@ def render(item: Item, idx: int, media: Path) -> None:
             "-c:a", "aac", "-shortest",
         ]
         if item.taken:
-            cmd += ["-metadata", f"creation_time={item.taken.isoformat()}Z"]
+            utc = item.taken.replace(tzinfo=HOME_TZ).astimezone(dt.timezone.utc)
+            cmd += ["-metadata", f"creation_time={utc.strftime('%Y-%m-%dT%H:%M:%S')}Z"]
     subprocess.run(cmd + [win(out)], check=True)
 
 
@@ -271,7 +294,7 @@ def main() -> int:
     # Pin mtimes last: exiftool rewrites (and so touches) the files.
     for it in items:
         when = it.mtime or it.taken or dt.datetime(2024, 1, 1)
-        ts = when.timestamp()
+        ts = when.replace(tzinfo=HOME_TZ).timestamp()  # not WSL's local zone
         os.utime(media / it.rel, (ts, ts))
 
     imported = 0
@@ -280,6 +303,7 @@ def main() -> int:
         shutil.copytree(a.import_dir, dest)  # copy: the source is never touched
         imported = sum(1 for p in dest.rglob("*") if p.is_file())
 
+    by_path = {it.rel: it for it in items}
     tags: dict[str, list[str]] = {}
     for it in items:
         for t in it.tags:
@@ -306,6 +330,8 @@ def main() -> int:
                 "taken": it.taken.isoformat() if it.taken else None,
                 "gps": it.gps, "camera": it.camera[1] if it.camera else None,
                 "tags": it.tags, "duplicate_of": it.copy_of,
+                # A duplicate carries its source's bytes, EXIF included.
+                "wall_clock": expected_wall_clock(by_path.get(it.copy_of, it)),
             }
             for it in items
         ],