Pre-share fixes from final review pass

Blockers
- http://birdnet.local/avian/ now serves the collage (added avian/index.html
  redirect to frontend/; previously the symlink target had no top-level
  index, so users saw a directory listing of api/ assets/ forwarding/
  frontend/ scripts/).
- Gemini model bumped from gemini-2.5-flash-image-preview (deprecated
  2026-01-15) to the stable gemini-2.5-flash-image. Pregen was non-
  functional out of the box.
- avian-mqtt.service: dropped %h (which expands to /root for system-mode
  units regardless of User=). Use WorkingDirectory=~ which DOES respect
  User=, plus a relative ExecStart.
- birdnet-api.php case 'lifelist' now aliases COUNT(*) AS n (was 'total'),
  matching what apt.js reads for atlas card counts. Atlas previously
  always displayed 0.

Bugs
- Retry-After parsing handles HTTP-date format without crashing.
- apt.js no longer fetches firstseen/timeseries (declared in state but
  never consumed). Two wasted round-trips per page load removed.
- update_birdnet.sh defaults branch=avian-visitors so the (opt-in)
  Sunday auto-update cron doesn't reset HEAD to upstream main and
  delete the avian/ overlay.
- recording.php: removed dead $BIRDS_JSON_CANDIDATES.

Polish
- Pregen --sleep default raised 4→6s (more headroom under free-tier RPM).
- en-dash in README BOM (~$35–80) replaced with hyphen for style match.
- Slop sweep across user-facing docs: no em-dashes, no en-dashes, no
  AI-slop word hits (robust/comprehensive/seamless/etc.).

avian/scripts/prompt.template.md

@@ -1,42 +1,25 @@
 # Bird illustration prompt
 
-This is the prompt sent to Gemini for every bird illustration. Edit it
-to change the style — the entire visual feel of the collage flows
-through this template.
+The prompt sent to Gemini for every illustration. Edit the body to change the style.
 
 Three placeholders get replaced per request:
 
-- `{sci_name}` — the binomial Latin name, e.g. `Calypte anna`
-- `{com_name}` — the English common name, e.g. `Anna's Hummingbird`
-- `{pose}` — either `perched` (pose 1) or `in flight with wings spread` (pose 2)
+- `{sci_name}` is the binomial Latin name, e.g. `Calypte anna`
+- `{com_name}` is the English common name, e.g. `Anna's Hummingbird`
+- `{pose}` is either `perched` (pose 1) or `in flight with wings spread` (pose 2)
 
-The default style below is **kachō-e** — Edo-period Japanese
-flower-and-bird woodblock prints, rendered in ink and watercolor.
-Replace the body below with whatever style feels right for your
-apartment.
+The default below is kachō-e (Edo-period Japanese flower-and-bird woodblock prints). Replace it with whatever style fits your apartment.
 
 ---
 
 ## Prompt
 
-Generate a {pose} {com_name} ({sci_name}) in the style of an Edo-period
-Japanese kachō-e woodblock print. Confident sumi-e ink linework with
-soft watercolor washes. Earthy, restrained palette — burnt umber,
-ochre, indigo, vermillion, muted greens. Plumage details rendered with
-short directional brush strokes; eye, beak, and feet drawn with crisp
-ink. The bird should be the only subject — NO background, NO branch
-unless the pose requires it (a single sparse twig is fine for
-perched), NO border or frame, NO text or signature.
+Generate a {pose} {com_name} ({sci_name}) in the style of an Edo-period Japanese kachō-e woodblock print. Confident sumi-e ink linework with soft watercolor washes. Earthy, restrained palette: burnt umber, ochre, indigo, vermillion, muted greens. Plumage details rendered with short directional brush strokes; eye, beak, and feet drawn with crisp ink. The bird is the only subject. NO background, NO branch unless the pose requires it (a single sparse twig is fine for perched), NO border or frame, NO text or signature.
 
 Anatomy must be biologically accurate for the named species:
 
 - Exactly two wings. Two legs. One head. One beak. One tail.
-- Posture and feather pattern matching {com_name} field-guide
-  references — color, markings, and body proportions must match the
-  real bird.
-- For perched poses: one wing folded against the body, the other
-  tucked behind. For flight: both wings extended in a natural flapping
-  position.
+- Posture, color, markings, and body proportions matching {com_name} field-guide references.
+- For perched poses: one wing folded against the body, the other tucked behind. For flight: both wings extended in a natural flapping position.
 
-Render at high resolution on a fully transparent background. The bird
-must be cut out cleanly — no shadow, no paper texture, no caption.
+Render at high resolution on a fully transparent background. Cut the bird out cleanly. No shadow, no paper texture, no caption.