Dates: serve the display wall clock (wall_clock) to clients

Every payload a client renders a capture time from now carries
`wall_clock`, a naive ISO-8601 string computed by the existing
`date_view::row_display_wall`: the camera's wall clock (true instant +
camera offset; the owner's display zone without an offset), with the
per-source fallback for unconverted rows. Clients render it verbatim and
do no zone math, which is the FileViewer-React #33 / Apollo #37 flip with
the rule kept server-side: the drain's permanent `date_utc IS NULL` floor
(#120: edited/exported files) would otherwise force every client to
carry the per-source legacy conventions forever, and insight prompts
already use the same function, so prompt and UI agree by construction.

- `/image/metadata` (+ the GPS / date / date-clear mutation responses):
  `file_wall_clock` — the row's wall, else the filename-class date, else
  the earliest fs time in the display zone (unindexed files).
- `/memories` items and `/photos/gps-summary` photos: `row_wall_clock`.
- `get_all_with_gps` returns full rows instead of a 7-tuple that dropped
  `date_taken_source`, which unconverted rows need.
- `date_view::owner_display_zone` resolves prefs -> app default per request.

Legacy fields are untouched, so current clients see byte-identical
responses (additive; safe to deploy ahead of the client flip, per #120).

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

CLAUDE.md

@@ -467,6 +467,18 @@ are SMS-derived and unaffected. Progress: Prometheus
 `date_backfill_remaining` per library on `GET /libraries` (live count of
 `date_utc IS NULL`).
 
+**Displaying a capture time: `wall_clock`.** Every payload a client renders a
+capture time from (`/image/metadata` + the date/GPS mutation responses,
+`/memories` items, `/photos/gps-summary`) carries `wall_clock`, a naive
+ISO-8601 string (`2018-09-29T14:00:00`) computed by
+`date_view::row_display_wall` — the camera's wall clock (instant + camera
+offset; the owner's display zone when there's no offset), with the per-source
+fallback for rows the drain can't convert (its permanent floor).
+`file_wall_clock` covers files with no row yet (filename date, then fs time).
+Clients render it verbatim and do no zone math (ADR-0001; FileViewer-React #33,
+Apollo #37). Insight prompts use the same function, so prompt and UI agree.
+`dev/e2e/e2e.sh check` verifies it for every fixture on all three endpoints.
+
 `/memories` is a single SQL query against this column
 (`get_memories_in_window` in `src/database/mod.rs`), using
 `strftime('%m-%d' | '%W' | '%m', date_taken, 'unixepoch', tz)` for