Add ISO A4 PDF print/book pipeline, page-frame prompts, and usage docs

Print and book PDF modes now letterbox each raster to A4 portrait at pdf.density;
print uses the matte color for pads. CLI forces 3:4 generation for print|book unless
--aspect-ratio is set. Cover, gallery, and back prompts gain DINA4PDF instructions when
those modes are active.

Introduce DescribePageFrame and PDF helpers with tests; add CLI tests for presentation
and aspect precedence. Expand README and config example with A4 examples, language
env vars, and page-format vs PDF behavior. Add sample Sumer vocabulary files.

Made-with: Cursor

1 files changed, 82 insertions, 2 deletions

diff --git a/README.md b/README.md
index f03b894..819da09 100644
--- a/README.md
+++ b/README.md
@@ -53,6 +53,13 @@ Environment variables also work. `COMICFORGE_` is the prefix, and dots in config
 - `COMICFORGE_PROVIDER_TEXT`
 - `COMICFORGE_MODELS_IMAGE`
 - `COMICFORGE_COMIC_STORY_PAGES`
+- `COMICFORGE_COMIC_GALLERY_PAGES`
+- `COMICFORGE_COMIC_ASPECT_RATIO`
+- `COMICFORGE_LANGUAGE_STORY_LANGUAGE`
+- `COMICFORGE_LANGUAGE_SCRIPT`
+- `COMICFORGE_PDF_DENSITY`
+- `COMICFORGE_PDF_JPEG_QUALITY`
+- `COMICFORGE_PDF_PRESENTATION`
 
 If `COMICFORGE_API_GOOGLE_API_KEY` is not set, ComicForge falls back to `GOOGLE_API_KEY`.
 
@@ -76,12 +83,22 @@ models:
 comic:
   story_pages: 5
   gallery_pages: 5
+  # Layout prompts: 4 panels require at least three horizontal rows (no 2×2-only grid).
   panels_per_page: 4
+  # Gemini image aspect ratio (e.g. 16:9 widescreen, 2:3 portrait comic page).
   aspect_ratio: "16:9"
   prompt_max_chars: 900
   page_max_retries: 5
   page_retry_base_seconds: 15
 
+# Final PDF assembly via ImageMagick `convert` (requires ImageMagick on PATH).
+pdf:
+  density: 150
+  # 0 = default PDF encoding; 1–100 = JPEG compression (smaller files).
+  jpeg_quality: 0
+  # none = full-bleed; print/book = ISO A4 portrait PDF pages (print = matte; book = aged + tilt + shadow + thick edge).
+  presentation: none
+
 story:
   realistic_weight: 0.4
 
@@ -101,6 +118,28 @@ prompts_dir: ./prompts
 
 `provider.*` currently supports Gemini in this codebase. Set `api.google_api_key`, `COMICFORGE_API_GOOGLE_API_KEY`, or fallback `GOOGLE_API_KEY` for Gemini-backed generation.
 
+### Page shape and PDF export
+
+**Image aspect ratio** controls both the Gemini generation API and the wording in prompt templates (widescreen vs tall comic page). It comes from configuration unless overridden on the command line.
+
+| Source | Effect |
+|--------|--------|
+| `comic.aspect_ratio` in YAML / env | Default ratio for the run (default `16:9`). Overridden when `pdf.presentation` is `print` or `book` (see next row), unless you set `--aspect-ratio`. |
+| `pdf.presentation` `print` or `book` (YAML / `COMICFORGE_PDF_PRESENTATION` / `--pdf-presentation`) | Unless `--aspect-ratio` is set on the CLI, forces `3:4` (closest Gemini ratio to **ISO A4** portrait, matching the PDF page size). This wins over `--page-format`. |
+| `--page-format screen` | Sets aspect ratio to `16:9` only when PDF mode is `none` and `--aspect-ratio` is unset. No effect when `pdf.presentation` is `print` or `book` (those modes force `3:4` unless you pass `--aspect-ratio`). |
+| `--page-format comic` | Sets aspect ratio to `2:3` under the same conditions as `screen` (not applied for `print` / `book` unless you override with `--aspect-ratio`). |
+| `--aspect-ratio <W:H>` | Explicit ratio (e.g. `16:9`, `2:3`, `3:4`, `21:9`). **Highest precedence** over `--page-format` and `pdf.presentation`. |
+
+**PDF assembly** (`pdf` in YAML or the flags below) only affects the multi-page comic PDF produced after all PNGs are rendered. It does not apply to manual `--prompt` mode (single PNG, no PDF). ImageMagick’s `convert` must be available to build the PDF.
+
+| Key / flag | Meaning |
+|------------|---------|
+| `pdf.density` / `COMICFORGE_PDF_DENSITY` | Passed to ImageMagick `-density` (default `150`). |
+| `pdf.jpeg_quality` / `COMICFORGE_PDF_JPEG_QUALITY` | `0` keeps the default encoding for the assembled PDF. Values `1`–`100` enable JPEG compression inside the PDF (smaller files, similar to a “compressed” comic PDF). |
+| `pdf.presentation` / `COMICFORGE_PDF_PRESENTATION` | `none` (default): full-bleed PDF pages (size follows source rasters). `print`: cream matte around the art, then **each page is fitted to ISO A4 portrait** (210×297 mm at `pdf.density`); cover, story, gallery, and back pages each become one A4 PDF page. Prompts add extra “single full sheet” instructions for cover / gallery / back. `book`: same **A4 page size** and the same per-page layout, after art is **aged** (mild sepia / desaturation, grain, vignette), then **tilt**, **drop shadow**, and a **thick page-edge** strip. |
+| `--pdf-jpeg-quality` | Same as `pdf.jpeg_quality` when set on the CLI. |
+| `--pdf-presentation` | `none`, `print`, or `book`; same as `pdf.presentation` when set on the CLI. |
+
 ## Usage
 
 ComicForge requires a vocabulary file:
@@ -116,12 +155,23 @@ Vocabulary lines can be:
 - `стол`
 - `= translation only`
 
+**Story language vs vocabulary script:** The story and visible text in panels must match `language.story_language` and `language.script` in config (e.g. Bulgarian + Cyrillic). If your word list is **English (Latin letters)** but the story is generated in **Cyrillic**, validation will fail when those Latin words appear in the story. For English stories with English/Latin vocabulary, set for example `story_language: English` and `script: Latin` in YAML, or for one run:
+
+```bash
+COMICFORGE_LANGUAGE_STORY_LANGUAGE=English COMICFORGE_LANGUAGE_SCRIPT=Latin \
+  comicforge --vocab english-words.txt --config config.yaml --output out
+```
+
 Useful flags:
 
 - `--output` sets the root output directory
 - `--prompt` generates a single image from a direct prompt and skips the story flow
 - `--prompts-dir` overrides the prompt template directory
 - `--style` and `--theme` override story generation hints and are also applied as context in manual prompt mode
+- `--page-format` `screen` or `comic` presets aspect ratio (`16:9` vs `2:3`) when PDF mode is `none`; see [Page shape and PDF export](#page-shape-and-pdf-export)
+- `--aspect-ratio` explicit `W:H` for Gemini (highest precedence over `--page-format`, `pdf.presentation`, and `comic.aspect_ratio`)
+- `--pdf-jpeg-quality` JPEG quality `0`–`100` for the assembled PDF (`0` = default encoding)
+- `--pdf-presentation` `none` (default), `print` (matte + **ISO A4** PDF pages), or `book` (aged art + tilt + shadow + thick edge + **same A4** pages); also sets generation to `3:4` unless `--aspect-ratio` is set
 - `--slug` forces the output folder name
 - `--narrate` enables narration output
 - `--narrator-voice` picks the Gemini narration voice
@@ -130,7 +180,7 @@ Useful flags:
 - `--ultra-realistic` and `--no-ultra-realistic` force photorealistic or classic comic rendering; without either flag ComicForge randomly chooses from the configured style families
 - `--version` prints the application version
 
-Example:
+Example (default PDF: full-bleed, aspect ratio from config):
 
 ```bash
 comicforge \
@@ -143,6 +193,36 @@ comicforge \
 
 The generated files are written under `out/comics/assets/demo-comic/`, with the gallery copied to `out/comics/gallery/` and the PDF written to `out/comics/PDF/`.
 
+**ISO A4 print PDF** (`print` fits every page to 210×297 mm at `pdf.density`; Gemini uses `3:4` unless you pass `--aspect-ratio`):
+
+```bash
+comicforge \
+  --vocab vocab.txt \
+  --config config.yaml \
+  --output out \
+  --slug my-a4-comic \
+  --pdf-presentation print
+```
+
+Shorter test run (fewer story and gallery pages) via env:
+
+```bash
+COMICFORGE_COMIC_STORY_PAGES=2 COMICFORGE_COMIC_GALLERY_PAGES=2 \
+  comicforge --vocab vocab.txt --config config.yaml --output out \
+  --slug a4-smoke --pdf-presentation print
+```
+
+**Book-style A4 PDF** (same page dimensions as `print`, plus aged paper, tilt, shadow, and page-edge treatment):
+
+```bash
+comicforge \
+  --vocab vocab.txt \
+  --config config.yaml \
+  --output out \
+  --slug my-a4-book \
+  --pdf-presentation book
+```
+
 For manual prompt mode:
 
 ```bash
@@ -151,4 +231,4 @@ comicforge --prompt "a robot reading a newspaper" --output out --slug manual-rob
 
 This writes a single image to `out/comics/assets/manual-robot/prompt.png`. Without `--slug`, ComicForge asks the text model for a short title and uses that as the directory slug, with a short deterministic fallback if title generation fails.
 
-Manual prompt mode can be combined with `--style`, `--theme`, and the ultra-realistic flags to shape the generated image prompt.
+Manual prompt mode can be combined with `--style`, `--theme`, `--page-format`, `--aspect-ratio`, and the ultra-realistic flags to shape the generated image prompt (page-shape flags affect the image API and the manual prompt template; PDF flags have no effect because no PDF is built).