Text warps: draw WordArt prstTxWarp presets, round-trip their adjusts

All 40 DrawingML text-warp presets now render instead of drawing flat text.
A warp is a list of bands over the shape's text rectangle (insets ignored):
fill bands stretch the ink of their lines between a top and a bottom guide
(positions by arc length, one horizontal scale for the whole text), follow
bands (arch, circle, button) set lines at natural size along an ellipse arc,
lines stacking outwards on parallel curves, with no wrapping. Lines are
shared over multi-band presets in order (ceil(n/k) per band).

The guide curves were fitted to PowerPoint renders of synthetic decks of
"I" bars (black-box observation, defaults and changed adjusts, 1-3 lines);
most presets match within about a point on a 420 x 200 pt box.

- geom: warp module (guides, presets, band mapping) with unit tests
- render: glyph outlines and underlines flattened, subdivided and mapped
- text: follow warps lay out without wrapping
- model/pptx: BodyProps.warp_adj read from and written to prstTxWarp/avLst

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

docs/file-format-parity.md

@@ -69,7 +69,7 @@ the round trip even though DeckCraft doesn't model it.
 | Effects: shadow, glow, soft edges, reflection | yes | yes | |
 | 3-D: `scene3d`, `sp3d` | kept | kept | Not rendered |
 | Text: runs, paragraphs, bullets, numbering, levels, autofit, columns, vertical, RTL, script fonts, fields, hyperlinks | yes | yes | Round-trip tests incl. `justLow` and date fields |
-| Text warp (`prstTxWarp`) | yes | yes | Not rendered |
+| Text warp (`prstTxWarp`) | yes | yes | All 40 presets rendered (`crates/geom/src/warp.rs`); adjust values (`avLst`) round-trip |
 | Pictures with crop, recolour, duotone, alpha, luminance | yes | yes | |
 | Tables with styles | yes | yes | |
 | Charts (`c:chartSpace`) | yes | yes | Original XML kept in `Chart.raw` |
@@ -99,4 +99,5 @@ the round trip even though DeckCraft doesn't model it.
 
 | Date | Change | Summary |
 |---|---|---|
+| 2026-10-12 | minor | Text warps rendered; their adjust values read and written |
 | 2026-10-10 | major | Created from PowerPoint 16.113.4's `CFBundleDocumentTypes`, `crates/pptx` reader/writer and tests, and the open round-trip issues |

docs/gaps.md

@@ -165,9 +165,13 @@ Detail in [animation-parity.md](animation-parity.md). 10–16 h; the pane is a *
 - **Estimate:** 4–6 h.
 
 ### Edit points, text warp, 3-D
-- **Evidence:** checklist rows "Edit points" (P1 missing), "Text warp transforms", "Bevel and 3-D
-  rotation" (missing; `scene3d`/`sp3d` kept as raw XML on round trip).
-- **Estimate:** 4–6 h (edit points), 6–10 h (warp), 8–12 h (3-D render approximation).
+- **Evidence:** checklist rows "Edit points" (P1 missing), "Text warp transforms" (partial: all 40
+  `prstTxWarp` presets render and their adjusts round-trip, but there is no Transform gallery or
+  command to apply one, no adjust handles, and arc/circle placement can differ from PowerPoint by
+  1–3 % of the path length), "Bevel and 3-D rotation" (missing; `scene3d`/`sp3d` kept as raw XML on
+  round trip).
+- **Estimate:** 4–6 h (edit points), 2–4 h (warp gallery, command and handles), 8–12 h (3-D render
+  approximation).
 
 ### Proofing: spelling, thesaurus, AutoCorrect
 - **Evidence:** `review.spelling` checks a small built-in list of frequent misspellings
@@ -247,5 +251,6 @@ Detail in [localization-parity.md](localization-parity.md).
 
 | Date | Change | Summary |
 |---|---|---|
+| 2026-10-12 | minor | Text warps render (all 40 presets, adjusts round-trip); the warp gap is now the gallery, command and handles |
 | 2026-10-10 | minor | Noted that no gap blocks alpha (core-workflow gate passes) |
 | 2026-10-10 | major | Created: every gap from the 2026-10-10 re-measure and the 16 open GitHub issues, ranked, with beta blockers marked |

docs/parity-checklist.md

@@ -9,7 +9,7 @@ The summary between `<!-- SUMMARY -->
 |---|---|---|---|---|---|
 | P0 | 72 | 60 | 12 | 0 | 92% |
 | P1 | 65 | 38 | 21 | 6 | 75% |
-| P2 | 54 | 13 | 13 | 28 | 36% |
+| P2 | 54 | 13 | 14 | 27 | 37% |
 
 | Area | Parity |
 |---|---|
@@ -18,7 +18,7 @@ The summary between `<!-- SUMMARY -->
 | Slides | 90% |
 | Views | 90% |
 | Masters & themes | 85% |
-| Shapes | 86% |
+| Shapes | 88% |
 | Format | 81% |
 | Arrange | 100% |
 | Text | 80% |
@@ -115,7 +115,7 @@ Open P0 items: Start screen (new, templates/themes, recent), Contextual tabs (Sh
 | Shapes | Change shape | P1 | D |
 | Shapes | Text boxes | P0 | D |
 | Shapes | WordArt | P1 | P |
-| Shapes | Text warp transforms | P2 | M |
+| Shapes | Text warp transforms | P2 | P |
 | Shapes | Shape quick styles | P1 | D |
 | Shapes | Set as default shape | P2 | D |
 | Format | Solid fill and transparency | P0 | D |