Merge PR #3438: fix(render): use unfiltered inline image byte length before EI heuristic (#3107)

docs/roadmap.md: main's M2 notes with the PR's sentence appended
ROADMAP.md: the PR's progress-log line moved to the top (newest first)

ROADMAP.md

@@ -174,6 +174,7 @@ Ranked; detail and the full milestone table in [docs/roadmap.md](docs/roadmap.md
 
 ## Progress log
 
+- **2026-10-22 (M2, #3107 / PR #3438):** Inline-image parsing falls back to the existing EI heuristic when missing declared samples, headers or terminators exceed the content-window budget, instead of waiting for an impossible allocation. Exact-length parsing for available samples and ordinary large streamed images is retained. Estimates unchanged.
 - **2026-10-20 (M6, calculation order page):** Prepare a form ▸ Calculation order, a page of its own, lists the calculated fields in the order they calculate with their formulas and values, moved with Up/Down arrows (as Acrobat's Set Field Calculation Order), Alt+↑/↓ or by dragging. A card says what is wrong with the order and holds Fix order; a loop has a card of its own that opens one of its formulas. On the page, each calculated field shows its step, and arrows show what the field in focus reads and what reads it. Estimates unchanged.
 - **2026-10-20 (M6, calculation order):** The order a form's fields calculate in (`/CO`) is read, checked, fixed and set headlessly with `form_calculation_order`: it says which fields read one calculated later (they show stale values), which read each other in a loop, and which the PDF's order leaves out; Fix order moves only what must move, in one undo step, and the form recalculates. Editing a formula no longer moves its field to the end of the order, and a field the order lists twice calculates once. Estimates unchanged.
 - **2026-10-20 (M2, #3574):** Forms without Resources use page Properties for ActualText and layer visibility. Synthetic tests cover boundaries, nested/shared forms, and save/reopen. Estimates unchanged.