Implement bounded deterministic fixed-layout EPUB generation (#417)

README.md

@@ -404,6 +404,10 @@ When `input_format` is omitted, Renderflow auto-detects the format from the file
 | `epub` | Renders a reflowable EPUB 3   | Pandoc            |
 | `kepub` | Renders EPUB 3, then Kobo enhancements | Pandoc + Kepubify |
 
+These document-source outputs are reflowable. The exact
+[fixed-layout EPUB route](docs/user-guide/fixed-layout-epub.md) uses an explicit,
+ordered PNG or JPEG collection with its own policy and publication metadata.
+
 Not every input → output combination is supported. For example, `epub` and `latex` inputs cannot currently be converted to `docx`. Renderflow reports a clear error when an unsupported combination is specified.
 
 **Image formats** (via FFmpeg):

ROADMAP.md

@@ -3,7 +3,7 @@ schema: aether.architecture-document/v1
 id: renderflow-roadmap
 title: Renderflow Roadmap
 kind: architecture-document
-version: 0.1.4
+version: 0.1.5
 status: draft
 owners:
   - egohygiene
@@ -26,6 +26,29 @@ supersedes: []
 
 # Renderflow Roadmap
 
+## 2026-09-28 fixed-layout EPUB implementation handoff
+
+[#417](https://github.com/egohygiene/renderflow/issues/417) adds the exact
+`ebook.generate.epub.fixed-layout` route to the canonical ordered-collection
+planner. The initial native packager accepts only homogeneous local PNG or JPEG
+pages with frozen IDs, digests, order, and geometry. A declared publication
+contract supplies title, issue identity, date, language, contributor, rights,
+cover selection, per-page descriptions, and accessibility metadata. Explicit
+LTR/RTL progression never mirrors source artwork. SVG is refused until safe
+parsing and fixture evidence support it. Deterministic package members, bounded
+inputs/output, retained run provenance, and unchanged source files are the #417
+review boundary.
+
+After #417 review and merge,
+[#418](https://github.com/egohygiene/renderflow/issues/418) independently
+validates fixed-layout EPUB 3.3 output and advertises exact capability truth;
+[#419](https://github.com/egohygiene/renderflow/issues/419) packages the
+immutable Renderflow integration candidate for
+[Flow #52](https://github.com/egohygiene/flow/issues/52). Neither this route nor
+the first three-input [#433](https://github.com/egohygiene/renderflow/issues/433)
+gallery claims fixed-layout KEPUB, retailer acceptance, complete accessibility,
+or publication approval. Later gallery expansion remains tracked by #412.
+
 ## 2026-09-28 artifact gallery review handoff
 
 [#433](https://github.com/egohygiene/renderflow/issues/433) is the first bounded

crates/renderflow-cli/Cargo.toml

@@ -36,6 +36,10 @@ path = "../../tests/ordered_collection_cli.rs"
 name = "artifact_gallery_cli"
 path = "../../tests/artifact_gallery_cli.rs"
 
+[[test]]
+name = "fixed_layout_epub_cli"
+path = "../../tests/fixed_layout_epub_cli.rs"
+
 [[test]]
 name = "graph_integration_test"
 path = "../../tests/graph_integration_test.rs"

crates/renderflow-core/data/tool-registry.yaml

@@ -1,6 +1,22 @@
 schema: renderflow.tool-registry/v1
 
 tools:
+  - id: tool.renderflow-epub
+    name: Renderflow fixed-layout EPUB packager
+    discovery:
+      kind: virtual
+    operating_systems: [linux, macos, windows]
+    capabilities:
+      - ebook.generate.epub.fixed-layout
+    input_media_types: [image/png, image/jpeg]
+    output_media_types: [application/epub+zip]
+    determinism: deterministic
+    locality: local
+    fidelity: lossless
+    support_tier: experimental
+    license_notes: "In-process Renderflow implementation; see the Renderflow repository license."
+    distribution_notes: "Exact bounded ordered-page PNG/JPEG route only; SVG, reflowable EPUB, fixed-layout KEPUB, retailer acceptance, and independent EPUB 3.3 conformance are separate contracts."
+
   - id: tool.lulu-rules
     name: Pinned Lulu publication rule pack
     discovery: