senyo888 · Oct 3, 2026 · Oct 3, 2026
diff --git a/.github/workflows/validate.yml b/.github/workflows/validate.yml
@@ -25,5 +25,11 @@ jobs:
       - name: Validate canonical catalogue surfaces
         run: python3 scripts/validate_catalog.py --base-ref "${{ github.event.pull_request.base.sha }}"
 
+      - name: Install preview validation dependency
+        run: python3 -m pip install -r requirements-dev.txt
+
+      - name: Validate preview timing and still alternatives
+        run: python3 scripts/validate_previews.py
+
       - name: Check patch whitespace
         run: git diff --check "${{ github.event.pull_request.base.sha }}...${{ github.event.pull_request.head.sha }}"
diff --git a/.gitignore b/.gitignore
@@ -7,6 +7,8 @@
 Thumbs.db
 *.swp
 *.tmp
+.venv/
+__pycache__/
 .playwright-cli/
 /work/
 

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
@@ -46,6 +46,7 @@ the gap is clear before you build the pull request.
    ```text
    pets/<pet-id>/
    site/assets/<pet-id>-preview.gif
+   site/assets/<pet-id>-preview.png
    site/install/<pet-id>/index.html
    catalog.json
    README.md
@@ -95,6 +96,7 @@ pets/<pet-id>/
 ├── pet.json
 ├── spritesheet.webp
 ├── preview.gif
+├── preview.png
 ├── README.md
 └── qa/
     ├── contact-sheet.png
@@ -178,15 +180,20 @@ python3 scripts/render_idle_preview.py \
   --output "pets/${PET_ID}/preview.gif"
 ```
 
-The command requires Python 3 and Pillow. The renderer preserves the standard idle
-timing, creates a `384 × 416` 2x presentation asset for clean browser downsampling, and
+The command requires Python 3 and Pillow; follow the [development setup](docs/MAINTENANCE.md).
+It renders a 6.6-second desktop-paced idle loop and matching static PNG at
+`384 × 416` size for clean browser downsampling (`--scale 1` uses native cells), and
 uses a deterministic alpha cutoff before GIF encoding. This prevents GIF's binary
 transparency from turning faint edge pixels into a grainy fringe. Copy the resulting
-preview to `site/assets/` when the pet is shown in the public catalogue.
+GIF and PNG to `site/assets/` when the pet is shown in the public catalogue.
+Use a `<picture>` source with `media="(prefers-reduced-motion: reduce)"` for the PNG
+on each website card and installer. The static image must equal GIF frame zero.
+Run `python3 scripts/validate_previews.py` in the activated development environment.
 
 The cache token is the first 12 lowercase characters of the exact referenced preview
 file's SHA-256. Package README references hash `pets/<pet-id>/preview.gif`; website and
-installer references hash `site/assets/<pet-id>-preview.gif`. The two previews may
+installer references hash `site/assets/<pet-id>-preview.gif` and the corresponding
+PNG separately. Package and site previews may
 differ after documented presentation-only cleanup.
 
 ## Change matrix

diff --git a/README.md b/README.md
@@ -13,13 +13,13 @@ An independent community catalogue of custom animated pets for the Codex desktop
 ![License](https://img.shields.io/badge/license-CC%20BY%204.0-fbbf24?style=flat-square)
 [![Give Codex Pets a star on GitHub](https://img.shields.io/github/stars/senyo888/codex-pets?style=flat-square&logo=github&label=Give%20us%20a%20star&color=fbbf24)](https://github.com/senyo888/codex-pets)
 
-<a href="pets/bella/README.md"><img src="pets/bella/preview.gif?v=1d01e149813d" alt="Bella's dimensional idle animation" width="150"></a>
-<a href="pets/aetherwing/README.md"><img src="pets/aetherwing/preview.gif?v=7d8ee08c4885" alt="AetherWing's calm idle animation" width="150"></a>
-<a href="pets/aethercore/README.md"><img src="pets/aethercore/preview.gif?v=ec0aa941a348" alt="AetherCore's polished metallic idle animation" width="150"></a>
-<a href="pets/aethermite/README.md"><img src="pets/aethermite/preview.gif?v=24eb2a800e48" alt="AetherMite's dimensional idle animation" width="150"></a>
-<a href="pets/aetherbite/README.md"><img src="pets/aetherbite/preview.gif?v=1c09298b9c11" alt="Aetherbite's cinematic idle animation" width="150"></a>
-<a href="pets/calian/README.md"><img src="pets/calian/preview.gif?v=73d2a0b50334" alt="Calian's calm idle animation" width="150"></a>
-<a href="pets/scarlet/README.md"><img src="pets/scarlet/preview.gif?v=49db273a1e1a" alt="Scarlet's calm idle animation" width="150"></a>
+<a href="pets/bella/README.md"><img src="pets/bella/preview.gif?v=13ab61440ccc" alt="Bella's dimensional idle animation" width="150"></a>
+<a href="pets/aetherwing/README.md"><img src="pets/aetherwing/preview.gif?v=cf75c61eac81" alt="AetherWing's calm idle animation" width="150"></a>
+<a href="pets/aethercore/README.md"><img src="pets/aethercore/preview.gif?v=ea06dabe0655" alt="AetherCore's polished metallic idle animation" width="150"></a>
+<a href="pets/aethermite/README.md"><img src="pets/aethermite/preview.gif?v=93af9b1c410e" alt="AetherMite's dimensional idle animation" width="150"></a>
+<a href="pets/aetherbite/README.md"><img src="pets/aetherbite/preview.gif?v=a3774afdaa8a" alt="Aetherbite's cinematic idle animation" width="150"></a>
+<a href="pets/calian/README.md"><img src="pets/calian/preview.gif?v=422116aef0a3" alt="Calian's calm idle animation" width="150"></a>
+<a href="pets/scarlet/README.md"><img src="pets/scarlet/preview.gif?v=f88c094046c2" alt="Scarlet's calm idle animation" width="150"></a>
 
 ## [Bella](pets/bella/README.md) · [AetherWing](pets/aetherwing/README.md) · [AetherCore](pets/aethercore/README.md) · [AetherMite](pets/aethermite/README.md) · [Aetherbite](pets/aetherbite/README.md) · [Calian](pets/calian/README.md) · [Scarlet](pets/scarlet/README.md)
 
@@ -44,7 +44,11 @@ An independent community catalogue of custom animated pets for the Codex desktop
 | 006 | [**Calian**](pets/calian/README.md) | Calian isolates decisive faults and restores deliberate control with calm, methodical judgement. | Sprite v2 | Validated and ready |
 | 007 | [**Scarlet**](pets/scarlet/README.md) | Scarlet pairs vigilant drift tracing with propulsive follow-through, carrying every correction to verified closure beside Calian. | Sprite v2 | Validated and ready |
 
-Each companion has a distinct identity and animation language. Every animated preview above is rendered directly from its current validated atlas.
+Each companion has a distinct identity and animation language. Every animated preview above is derived from its current validated atlas and uses a
+6.6-second idle loop, matching the desktop renderer checked in version 26.930.21537.
+The website displays still images when reduced motion is requested; each pet README
+also links to a static preview.
+See [maintenance and compatibility checks](docs/MAINTENANCE.md).
 
 ### Calian and Scarlet — the sister act
 
@@ -117,6 +121,7 @@ codex-pets/
 │       ├── pet.json
 │       ├── spritesheet.webp
 │       ├── preview.gif
+│       ├── preview.png
 │       ├── README.md
 │       └── qa/
 ├── site/

diff --git a/docs/CATALOG_CONTRACT.md b/docs/CATALOG_CONTRACT.md
@@ -136,3 +136,16 @@ output, external availability, or real desktop-app installer behaviour.
 - A successful Pages deployment and live readback are required before publication is
   declared complete.
 - No validator, agent, workflow, or generated output may approve its own work.
+
+## Preview playback and accessibility
+
+Package and site idle GIFs use six frames with durations of 1680, 660, 660, 840,
+840, and 1920 ms (6.6 seconds total), matching the desktop renderer inspected in
+26.930.21537. This is a dated presentation baseline, not a package timing override.
+Each GIF has a same-stem static PNG equal to its first decoded frame. Website cards
+and installers select that PNG through a reduced-motion `<picture>` source.
+PNG cache tokens follow the same exact-file SHA-256 rule as GIF tokens.
+
+`python3 scripts/validate_previews.py` checks timing, geometry, transparency, disposal,
+looping, and still-frame equality using the pinned development dependency. The standard
+library catalogue validator checks source markup, tokens, and local PNG references.
diff --git a/docs/MAINTENANCE.md b/docs/MAINTENANCE.md
@@ -0,0 +1,57 @@
+# Maintenance and compatibility
+
+## Development setup
+
+Use Python 3.12 or newer and a complete Git installation with HTTPS helpers.
+Keep image tooling in a project environment rather than installing into system Python:
+
+```sh
+python3 -m venv .venv
+. .venv/bin/activate
+python -m pip install -r requirements-dev.txt
+python scripts/validate_catalog.py
+python scripts/validate_previews.py
+```
+
+Repeat setup for each checkout. The standard-library catalogue check can also run
+without the environment. CI installs the same pinned Pillow dependency for previews.
+If Git reports a missing `remote-https`, inspect `git --exec-path` and the selected
+Git distribution; restore its matching helper directory rather than changing credentials.
+
+## October 2026 maintenance changes
+
+- Idle previews now use a 6.6-second loop rather than the previous 1.1-second loop.
+  Timing was checked against desktop app 26.930.21537 on 2026-10-03. Original decoded
+  GIF artwork is retained; only frame delays changed.
+- Static PNG alternatives show frame zero under reduced motion on the catalogue and
+  every installer. GIF and PNG cache tokens track the exact referenced files.
+- Preview validation runs in CI alongside catalogue validation.
+- Authoritative atlases, package IDs, descriptions, sprite versions, installer queries,
+  and published v1.0.0 release assets are unchanged by these presentation changes.
+
+## Runtime boundaries
+
+The desktop app owns playback, state priority, pointer responses, pet size, and
+reduced-motion handling. Package artwork does not implement agent reasoning or control
+Home Assistant. Changing preview timing cannot change installed runtime timing.
+
+Desktop v2 atlases and ChatGPT web derivatives have separate contracts. Desktop files
+are local; web adoption links and uploads are separate distribution records. Do not
+replace an eleven-row desktop atlas with a nine-row web export.
+
+Sources: [Pets](https://learn.chatgpt.com/docs/pets) and
+[September 11 pet controls update](https://learn.chatgpt.com/docs/changelog), checked
+2026-10-03. Recheck renderer timing on future app updates before changing this baseline.
+
+## Validation before distribution
+
+Run both validators, inspect catalogue and all installers at desktop and 390 px mobile
+widths, and switch reduced motion both ways. Confirm each loaded still is static and
+matches the visible idle character. Check for image failures, overflow, console errors,
+and unchanged install actions. Preview-only changes do not require reinstalling atlases.
+For installed packages, compare both pet.json and spritesheet bytes with the chosen
+canonical package; preserve prior files before synchronizing metadata.
+
+For an artwork change, rerun structural and visual QA across all states and directions,
+update hashes and previews together, and verify at actual display sizes. A frame-difference
+outlier alone is not sufficient evidence to regenerate a character.
diff --git a/pets/aetherbite/README.md b/pets/aetherbite/README.md
@@ -4,14 +4,16 @@
 
 **The Bio-Digital Systems Tinkerer**
 
-<img src="preview.gif?v=1c09298b9c11" alt="Aetherbite's cinematic idle animation" width="240">
+<img src="preview.gif?v=a3774afdaa8a" alt="Aetherbite's cinematic idle animation" width="240">
 
 *Humidity Intelligence's cinematic dimensional systems tinkerer, with crystalline wings, layered articulated armour, and expressive motion.*
 
 [**Install Aetherbite**](https://senyo888.github.io/codex-pets/install/aetherbite/)
 
 </div>
 
+[View the static idle preview](preview.png)
+
 ## Personality
 
 Aetherbite is energetic, resolute, and inventive. It brings a compact but dimensional presence to systems work while keeping the same practical instinct: observe carefully, explain the change, and improve the smallest useful thing first.

diff --git a/pets/aetherbite/preview.gif b/pets/aetherbite/preview.gif
diff --git a/pets/aetherbite/preview.png b/pets/aetherbite/preview.png
diff --git a/pets/aethercore/README.md b/pets/aethercore/README.md
@@ -4,14 +4,16 @@
 
 **The Continuity Engine**
 
-<img src="preview.gif?v=ec0aa941a348" alt="AetherCore's polished metallic idle animation" width="240">
+<img src="preview.gif?v=ea06dabe0655" alt="AetherCore's polished metallic idle animation" width="240">
 
 *A calm clockwork guardian built to keep decisions connected, drift visible, and governance coherent.*
 
 [**Install AetherCore**](https://senyo888.github.io/codex-pets/install/aethercore/)
 
 </div>
 
+[View the static idle preview](preview.png)
+
 ## Personality
 
 AetherCore is measured, dependable, and quietly vigilant. It treats continuity as a living system: decisions should remain traceable, architectural intent should survive change, and hidden drift should never be allowed to accumulate unnoticed.

diff --git a/pets/aethercore/preview.gif b/pets/aethercore/preview.gif
diff --git a/pets/aethercore/preview.png b/pets/aethercore/preview.png
diff --git a/pets/aethermite/README.md b/pets/aethermite/README.md
@@ -4,14 +4,16 @@
 
 **The Systems Tinkerer**
 
-<img src="preview.gif?v=24eb2a800e48" alt="AetherMite's dimensional idle animation" width="240">
+<img src="preview.gif?v=93af9b1c410e" alt="AetherMite's dimensional idle animation" width="240">
 
 *A premium dimensional Humidity Intelligence champion with a layered mechanical shell and luminous environmental core.*
 
 [**Install AetherMite**](https://senyo888.github.io/codex-pets/install/aethermite/)
 
 </div>
 
+[View the static idle preview](preview.png)
+
 ## Personality
 
 AetherMite is curious, energetic, and inventive. It notices tiny inconsistencies, explores practical refinements, and prefers small explainable improvements over clever but fragile shortcuts.

diff --git a/pets/aethermite/preview.gif b/pets/aethermite/preview.gif
diff --git a/pets/aethermite/preview.png b/pets/aethermite/preview.png
diff --git a/pets/aetherwing/README.md b/pets/aetherwing/README.md
@@ -4,14 +4,16 @@
 
 **Pet 002 · The Runtime Sentinel**
 
-<img src="preview.gif?v=7d8ee08c4885" alt="AetherWing's calm idle animation" width="240">
+<img src="preview.gif?v=cf75c61eac81" alt="AetherWing's calm idle animation" width="240">
 
 *A flight-first guardian of deterministic control, architectural discipline, and truth-backed runtime behaviour.*
 
 [**Install AetherWing**](https://senyo888.github.io/codex-pets/install/aetherwing/)
 
 </div>
 
+[View the static idle preview](preview.png)
+
 ## Personality
 
 AetherWing watches the boundary between intent and execution. She challenges weakened architecture, detects drift early, and protects deterministic behaviour without disrupting stable systems.

diff --git a/pets/aetherwing/preview.gif b/pets/aetherwing/preview.gif
diff --git a/pets/aetherwing/preview.png b/pets/aetherwing/preview.png
diff --git a/pets/bella/README.md b/pets/bella/README.md
@@ -4,14 +4,16 @@
 
 **The 1 True Source**
 
-<img src="preview.gif?v=1d01e149813d" alt="Bella's dimensional idle animation" width="240">
+<img src="preview.gif?v=13ab61440ccc" alt="Bella's dimensional idle animation" width="240">
 
 *A premium dimensional crystalline coherence guardian with layered depth, graceful flight, and a precise eye for truth.*
 
 [**Install Bella**](https://senyo888.github.io/codex-pets/install/bella/)
 
 </div>
 
+[View the static idle preview](preview.png)
+
 ## Personality
 
 Bella is composed, precise, and gently sceptical. She prefers truth over theatre, deterministic systems over hidden magic, and a clean review over an enthusiastic guess.

diff --git a/pets/bella/preview.gif b/pets/bella/preview.gif
diff --git a/pets/bella/preview.png b/pets/bella/preview.png
diff --git a/pets/calian/README.md b/pets/calian/README.md
@@ -4,14 +4,16 @@
 
 **The Tactical Sentinel**
 
-<img src="preview.gif?v=73d2a0b50334" alt="Calian's calm idle animation" width="240">
+<img src="preview.gif?v=422116aef0a3" alt="Calian's calm idle animation" width="240">
 
 *A composed tactical guardian and one half of a sister act of unmatched diligence, known for calm judgement, deliberate control, and exact follow-through.*
 
 [**Install Calian**](https://senyo888.github.io/codex-pets/install/calian/)
 
 </div>
 
+[View the static idle preview](preview.png)
+
 ## Personality
 
 Calian is calm, tactical, and steady under pressure. She isolates the decisive fault, establishes a clear plan, and restores control with measured action.

diff --git a/pets/calian/preview.gif b/pets/calian/preview.gif
diff --git a/pets/calian/preview.png b/pets/calian/preview.png
diff --git a/pets/scarlet/README.md b/pets/scarlet/README.md
@@ -4,14 +4,16 @@
 
 **The Propulsive Execution Guardian**
 
-<img src="preview.gif?v=49db273a1e1a" alt="Scarlet's calm idle animation" width="240">
+<img src="preview.gif?v=f88c094046c2" alt="Scarlet's calm idle animation" width="240">
 
 *A poised CGI guardian and one half of a sister act of unmatched diligence, built to trace drift and carry every correction to verified closure.*
 
 [**Install Scarlet**](https://senyo888.github.io/codex-pets/install/scarlet/)
 
 </div>
 
+[View the static idle preview](preview.png)
+
 ## Personality
 
 Scarlet is poised, vigilant, and exacting. She follows weak signals across the full execution path, contains drift before it spreads, and closes gaps with controlled precision.

diff --git a/pets/scarlet/preview.gif b/pets/scarlet/preview.gif
diff --git a/pets/scarlet/preview.png b/pets/scarlet/preview.png
diff --git a/requirements-dev.txt b/requirements-dev.txt
@@ -0,0 +1 @@
+Pillow==12.3.0
diff --git a/scripts/render_idle_preview.py b/scripts/render_idle_preview.py
@@ -1,5 +1,5 @@
 #!/usr/bin/env python3
-"""Render a crisp six-frame idle GIF from a validated Codex v2 atlas."""
+"""Render a six-frame idle GIF and matching still from a validated Codex v2 atlas."""
 
 from __future__ import annotations
 
@@ -13,7 +13,9 @@
 ATLAS_SIZE = (1536, 2288)
 CELL_SIZE = (192, 208)
 IDLE_FRAME_COUNT = 6
-IDLE_DURATIONS = [280, 110, 110, 140, 140, 320]
+# Desktop renderer observed in 26.930.21537: base idle holds multiplied by six.
+# Presentation timing only; pet.json cannot override the app's animation timing.
+IDLE_DURATIONS = [1680, 660, 660, 840, 840, 1920]
 DEFAULT_ALPHA_THRESHOLD = 192
 DEFAULT_SCALE = 2
 
@@ -132,6 +134,9 @@ def main() -> None:
     )
 
     result = validate_preview(output, args.scale)
+    with Image.open(output) as preview:
+        preview.convert("RGBA").save(output.with_suffix(".png"))
+    result["stillOutput"] = str(output.with_suffix(".png"))
     result["spritesheet"] = str(spritesheet)
     result["alphaThreshold"] = args.alpha_threshold
     print(json.dumps(result, indent=2))

diff --git a/scripts/validate_catalog.py b/scripts/validate_catalog.py
@@ -68,9 +68,9 @@ def __init__(self) -> None:
         self.values: list[str] = []
 
     def handle_starttag(self, _tag: str, attrs: list[tuple[str, str | None]]) -> None:
-        """Record href and src values from an HTML start tag."""
+        """Record href, src, and single-candidate srcset values from an HTML start tag."""
         values = dict(attrs)
-        for key in ("href", "src"):
+        for key in ("href", "src", "srcset"):
             if values.get(key):
                 self.values.append(values[key] or "")
 
@@ -300,11 +300,13 @@ def validate_package(
         metadata_path,
         spritesheet,
         preview,
+        preview.with_suffix(".png"),
         readme,
         validation,
         ROOT / "pets" / pet_id / "qa" / "contact-sheet.png",
         ROOT / "pets" / pet_id / "qa" / "look-directions.png",
         site_preview,
+        site_preview.with_suffix(".png"),
         installer,
     )
     for path in required_paths:
@@ -503,6 +505,12 @@ def text_value(value: object) -> str:
     return html.escape(str(value), quote=False)
 
 
+def still_token(pet_id: str) -> str:
+    """Missing stills are reported by package validation, without a hash traceback."""
+    path = SITE_ROOT / "assets" / f"{pet_id}-preview.png"
+    return sha256(path)[:12] if path.is_file() else ""
+
+
 def validate_site_index(
     pets: list[dict[str, object]], site_tokens: dict[str, str], errors: list[str]
 ) -> None:
@@ -528,6 +536,7 @@ def validate_site_index(
         presentation = pet["presentation"]
         token = site_tokens[pet_id]
         required_snippets = (
+            f'<source media="(prefers-reduced-motion: reduce)" srcset="./assets/{pet_id}-preview.png?v={still_token(pet_id)}">',
             f'src="./assets/{pet_id}-preview.gif?v={token}" alt="{presentation["previewAlt"]}"',
             f'<p class="pet-number">Pet {pet["catalogueNumber"]}</p>',
             f'id="{pet_id}-title"',
@@ -564,6 +573,7 @@ def validate_installer(
     text = path.read_text(encoding="utf-8")
     readme_url = f"https://github.com/senyo888/codex-pets/blob/main/pets/{pet_id}/README.md"
     required_snippets = (
+        f'<source media="(prefers-reduced-motion: reduce)" srcset="../../assets/{pet_id}-preview.png?v={still_token(pet_id)}">',
         (
             f'<meta name="description" content="Install {name}, a custom animated '
             f'v{pet["spriteVersionNumber"]} pet for the Codex desktop app.">'
-Original file line number
+Diff line change
@@ Expand Up / @@ -7,6 +7,8 @@ @@
     Thumbs.db
     *.swp
     *.tmp
+    .venv/
+    __pycache__/
     .playwright-cli/
     /work/
@@ Expand Down @@