README intro.gif: green macOS wallpaper + richer mouse/command demo (#44)

* docs(media): green wallpaper and richer intro.gif demo

Replace the synthetic teal desktop with a photographed forest backdrop,
walk the pointer through titlebar/composer/slash/tools, and extend the
signed lock storyboard past splash → type → working.

Co-authored-by: Mathis <echobt@users.noreply.github.com>

* docs(media): regenerate intro.gif on forest desktop

Render the expanded lock storyboard through the official pipeline and
keep a 10-step pointer orbit so holds stay unique after GIF quantisation.

Co-authored-by: Mathis <echobt@users.noreply.github.com>

* fix(tui): split hero scenes out of lock_boards

Move HeroScene/paint_hero into readme_hero_boards so lock_boards stays
under its main-line count and the source-policy gate stops regressing.
Banner-green focus is unchanged.

Co-authored-by: Mathis <echobt@users.noreply.github.com>

* fix(scripts): isolate preview resize from ansi height

Preview downscaling rebound the manifest terminal height, so later
ANSI frames were padded to ~805 rows. Keep a preview-local height.

Co-authored-by: Mathis <echobt@users.noreply.github.com>

---------

Co-authored-by: Cursor Agent <cursoragent@cursor.com>
Co-authored-by: Mathis <echobt@users.noreply.github.com>

Author: echobt

CHANGELOG.md

@@ -9,6 +9,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Unreleased
 
+### Changed
+- README `docs/media/intro.gif` sits on a photographed green forest desktop (not teal blobs): Terminal chrome, a pointer that walks titlebar → composer → slash / model → Shell, and the signed lock TUI. Local CLI only — no Cortex Cloud handoff in the banner story.
+
 ## 0.1.9
 
 ### Changed

README.md

@@ -18,11 +18,11 @@
   <a href="https://cortex.foundation">cortex.foundation</a>
 </p>
 
-![Animated green Cortex CLI in a complete Terminal window on a macOS-styled desktop, with a moving pointer](./docs/media/intro.gif)
+![Cortex CLI in macOS Terminal on a green forest desktop: splash, prompt, slash commands, a Shell tool row, and a moving pointer](./docs/media/intro.gif)
 
-*Generated macOS-styled demo, not a desktop recording. The green CLI frames
-come from the offline `readme_hero` renderer; the desktop and pointer are
-composited. No live coding request is performed.*
+*Generated macOS desktop demo, not a screen recording. The TUI frames come
+from the offline `readme_hero` lock boards; the forest wallpaper, Terminal
+chrome and pointer are composited. No live coding request is performed.*
 Regenerate with `./scripts/render-demo-gif.sh` (Cargo, Python with Pillow, and
 FFmpeg required); terminal pixels are preserved 1:1 before GIF quantization.
 
@@ -184,8 +184,9 @@ The banner above is generated from this repository, not captured by hand:
 ./scripts/render-demo-gif.sh
 ```
 
-That records the signed lock TUI (splash → typing → working) headlessly
-through `generate_tui_demo` and rasterises the frames into `docs/media/intro.gif`.
+That records the signed lock TUI (splash → type a prompt → working → slash
+palette → `/model` → Shell → composer) headlessly through `generate_tui_demo`
+and composites it onto the forest desktop in `docs/media/intro.gif`.
 
 ## Release and CI secrets
 

docs/README.md

@@ -8,7 +8,7 @@ servers, skills, agents, plugins, hooks, sessions and permissions.
 New here? Start with **[Getting started](guides/getting-started.md)**, then keep
 **[CLI reference](reference/cli.md)** open in another tab.
 
-![Cortex Code running a change end to end](media/intro.gif)
+![Cortex CLI in macOS Terminal on a green forest desktop, touring slash commands and a live tool row](media/intro.gif)
 
 ## Contents