Add nerd glasses and the ...because he was bored... subtitle to the loading screen

docs/BRANDING.md

@@ -9,10 +9,11 @@ The stock Godot boot splash (logo plus "GODOT Game engine") is replaced by the
 
 ## Asset
 
-`assets/branding/boot_splash.png`, 1024x1185, palette PNG with alpha
-(256 colors, 95 alpha levels), about 159 KB. Subject: cartoon zombie head and bust,
-bald scalp with a sparse hair fringe on the sides, unsettling grin, thumbs up, with
-"MatGames" below (one word, no space) in a phosphor-terminal typeface.
+`assets/branding/boot_splash.png`, 1024x1315, palette PNG with alpha
+(256 colors, 95 alpha levels), about 171 KB. Subject: cartoon zombie head and bust,
+bald scalp with a sparse hair fringe on the sides, thick nerd glasses, unsettling grin,
+thumbs up, with "MatGames" (one word, no space) in a phosphor-terminal typeface and
+the subtitle `"...because he was bored..."` beneath it.
 
 Provenance is recorded in `tools/branding/manifest.json`:
 
@@ -20,8 +21,10 @@ Provenance is recorded in `tools/branding/manifest.json`:
   `gemini-3.1-flash-image`) on 2026-10-11 from no third-party source material; the
   provider terms do not claim ownership of the output. A second AI pass (`agy_edit`)
   kept the face, grin, thumbs-up hand, shirt, pose and flat background and changed
-  only the hair to a bald scalp with a side fringe; both files and their SHA256 are
-  kept in `tools/branding/raw/` and the edit is recorded under `mascot_derived_from`.
+  only the hair to a bald scalp with a side fringe, then a third pass added thick nerd
+  glasses while keeping the face, grin, hand, shirt, pose and flat background. All
+  files and their SHA256 are kept in `tools/branding/raw/` and the chain is recorded
+  under `mascot_provenance`.
   Note that an image generator does not emit real alpha, so the flat magenta
   background is keyed out locally;
 - lettering: drawn by script, not by the generator, because generated text is
@@ -45,8 +48,11 @@ packed into the export (`tools/*` is already excluded by the export preset).
    pink tongue or the blue shirt because their red and blue are not both above green;
 4. crops to the subject, applies a 50 px fade at the bottom to soften the frame cut
    of the generated bust, and scales to 1024 px wide with 40 px side padding;
-5. draws the title with VT323 in amber over a blurred glow layer. The title defaults
-   to the one-word form `MatGames`; pass `--title` to change it;
+5. draws the title with VT323 in amber over a blurred glow layer, plus an optional
+   second line. Defaults are the one-word `MatGames` and the subtitle
+   `"...because he was bored..."`; `--title`, `--subtitle` (empty to omit) and
+   `--subtitle-height` change them. A 30 px `--bottom-padding` band is left under the
+   text so the shell progress bar does not cross the lettering;
 6. quantizes to 256 colors (no dither) and writes the PNG plus the manifest.
 
 ```sh
@@ -71,11 +77,11 @@ ratio; the exported shell confirms the result with the classes
 
 ## Verification
 
-- Exported `index.png` has the same 1024x1185 dimensions as the master. It is
-  re-encoded by the exporter to 32-bit RGBA (about 496 KB), so the bytes are not
-  identical; composited on black the two images differ by at most 6.4/255 on
-  0.13% of pixels, all with alpha below 20, i.e. invisible. The release keeps the
-  159 KB master in the repository and ships a gzip sidecar.
+- Exported `index.png` has the same 1024x1315 dimensions as the master. It is
+  re-encoded by the exporter to 32-bit RGBA (about 528 KB), so the bytes are not
+  identical; composited on black the two images differ by at most 5.8/255 on
+  0.11% of pixels, all with alpha below 20, i.e. invisible. The release keeps the
+  171 KB master in the repository and ships a gzip sidecar.
 - The exported shell contains no "Game engine" text and the splash image has an
   empty `alt`.
 - `html/export_icon=false`, so no favicon is exported: the browser tab still shows