feat: add vse-cut-list example witnessing the 4.5-to-5.x sequencer API rename

AI-generated VSE code still targets the pre-rename API everywhere:
sequence_editor.sequences is gone on 5.x, new_effect ends strips with
length= there but frame_end= on 4.5, and frame_final_* reads are
deprecated aliases for left_handle/right_handle/duration. No existing
example covers the sequencer, so this drift had no smoke-gated witness.

The example builds a deterministic cut list (color programs, a clamped
GAMMA_CROSS fed by a dedicated source pair, a scene strip, a text strip),
asserts every span against its closed form on each version's canonical
accessors, and re-asserts after a save/reload round-trip. A --check-pixels
mode witnesses the compositing contract on a tiny render. Hazards found
while authoring are witnessed too: the cross clamps to the source overlap,
effect strips consume their inputs only when stacked above them, and a
same-scene scene strip renders transparent.

Runs check-only on 4.5 LTS and 5.1 in blender-smoke; the render is the
sequencer's own output staged in the dark studio per VISUAL-STYLE, gated
against the pinned contact-sheet set.

Signed-off-by: fOuttaMyPaint <TMhospitalitystrategies@gmail.com>

Author: TMHSDigital

.cursor-plugin/plugin.json

@@ -80,6 +80,7 @@
     "examples/text-version-stamp",
     "examples/turntable",
     "examples/uv-layer-grid",
+    "examples/vse-cut-list",
     "examples/wave-displace"
   ]
 }

.github/workflows/blender-smoke.yml

@@ -350,3 +350,22 @@ jobs:
           # non-zero on failure.
           xvfb-run -a "$BLENDER" --background \
             --python examples/png-exr-alpha/png_exr_alpha.py --
+
+      - name: Shipped example - vse cut list (sequencer 4.5 vs 5.x rename)
+        run: |
+          set -euo pipefail
+          # Check only (no render): asserts the accessor rename (.sequences
+          # gone on 5.x, bridged on 4.5), the new_effect end-kwarg rename
+          # (frame_end on 4.5, length on 5.x — the wrong kwarg TypeErrors),
+          # closed-form spans on each version's canonical accessors
+          # (frame_final_* vs left_handle/right_handle/duration with the
+          # deprecation bridge), GC wiring and clamping, scene-strip span,
+          # and a save/reload round-trip. Exits non-zero on failure.
+          xvfb-run -a "$BLENDER" --background \
+            --python examples/vse-cut-list/vse_cut_list.py --
+          # Compositing witness on a tiny Cycles render: mosaic cells carry
+          # their strip colors, the cross cell is a true mid blend, and a
+          # consumed cross source never composites independently.
+          xvfb-run -a "$BLENDER" --background \
+            --python examples/vse-cut-list/vse_cut_list.py -- \
+            --check-pixels --engine cycles

AGENTS.md

@@ -20,7 +20,7 @@ a `.cursor-plugin/plugin.json` manifest so the ecosystem drift checker
 classifies it as a `cursor-plugin`. This is content the AI loads when the user
 asks Blender questions or works on Blender add-ons in Cursor or Claude Code.
 
-The content base is 12 skills, 6 rules, 2 templates, 17 snippets, and 22
+The content base is 12 skills, 6 rules, 2 templates, 17 snippets, and 23
 examples (counts are CI-enforced against README.md and the manifest). The full
 inventory tables and per-item purposes live in `CLAUDE.md`. Example anatomy
 and authoring rules: copy `examples/bmesh-gear/`; the render look is specified
@@ -35,7 +35,7 @@ Blender-Developer-Tools/
   rules/<rule-name>.mdc          # 6 rule files
   templates/<template-name>/     # 2 starter templates
   snippets/<snippet-name>.py     # 17 standalone Python snippets
-  examples/<name>/               # 22 runnable smoke-gated examples (+ gallery.json)
+  examples/<name>/               # 23 runnable smoke-gated examples (+ gallery.json)
   scripts/build_gallery.py       # generates docs/gallery/ (stdlib only)
   scripts/site/                  # vendored landing-page build (build_site.py + template)
   docs/gallery/                  # committed generated gallery pages + hero assets

CLAUDE.md

@@ -21,7 +21,7 @@ skills/<skill-name>/SKILL.md   - AI workflow definitions, 12 total
 rules/<rule-name>.mdc          - Anti-pattern rules, 6 total
 templates/<template-name>/     - Starter projects, 2 total
 snippets/<snippet-name>.py     - Standalone code patterns, 17 total
-examples/<name>/               - Runnable smoke-gated examples, 22 total (+ gallery.json)
+examples/<name>/               - Runnable smoke-gated examples, 23 total (+ gallery.json)
 scripts/build_gallery.py       - Regenerates docs/gallery/ from gallery.json (stdlib only)
 scripts/site/                  - Vendored landing-page build (Jinja2)
 docs/gallery/                  - Committed generated gallery pages + hero renders
@@ -82,11 +82,11 @@ v0.1.0: canonical object creation and deletion, depsgraph evaluated mesh, bmesh
 
 v0.2.0: Principled BSDF material, driver-with-custom-function via `driver_namespace`, application handler registration, shader node group with cross-version `interface` API, `foreach_get` bulk vertex read, version-branch skeleton, and USD export with `evaluation_mode='RENDER'`.
 
-## Examples (22)
+## Examples (23)
 
 Runnable scripts at `examples/<name>/`, each asserting a real API contract with
 deterministic checks (exit non-zero on failure) and optionally rendering a still via
-`--output`. All twenty-two run headless on Blender 4.5 LTS and 5.1 in `blender-smoke.yml`;
+`--output`. All twenty-three run headless on Blender 4.5 LTS and 5.1 in `blender-smoke.yml`;
 their renders ship in the site gallery at `docs/gallery/`. `examples/gallery.json` is the
 gallery's source of truth. When authoring a new one, copy the anatomy of
 `examples/bmesh-gear/` (script structure, README shape, dark-studio render recipe) and

README.md

@@ -18,7 +18,7 @@
 </p>
 
 <p align="center">
-  <strong>12 skills</strong> &nbsp;&bull;&nbsp; <strong>6 rules</strong> &nbsp;&bull;&nbsp; <strong>2 templates</strong> &nbsp;&bull;&nbsp; <strong>17 snippets</strong> &nbsp;&bull;&nbsp; <strong>22 examples</strong>
+  <strong>12 skills</strong> &nbsp;&bull;&nbsp; <strong>6 rules</strong> &nbsp;&bull;&nbsp; <strong>2 templates</strong> &nbsp;&bull;&nbsp; <strong>17 snippets</strong> &nbsp;&bull;&nbsp; <strong>23 examples</strong>
 </p>
 
 <p align="center">
@@ -285,6 +285,21 @@ A depsgraph-evaluated export — builds a cube with `SUBSURF`, measures the eval
 `evaluated_get().to_mesh()` / `to_mesh_clear()`, and asserts `wm.obj_export` ships the
 modifier-applied geometry (exported vertex count == evaluated > base).
 
+</td>
+</tr>
+<tr>
+<td width="46%" valign="middle">
+<a href="examples/vse-cut-list/"><img src="examples/vse-cut-list/preview.webp" alt="VSE cut list: a two-by-two program wall in a dark studio — crimson, teal, and amber color strips plus the mid cross-blend cell, composited by the sequencer over a scene strip, with the span caption below" /></a>
+</td>
+<td valign="middle">
+
+### [vse-cut-list](examples/vse-cut-list/)
+
+The sequencer API rename from 4.5 LTS to 5.x — `strips` (never `.sequences`), `new_effect`
+ending in `length=` vs `frame_end=`, and `left_handle`/`right_handle`/`duration` replacing
+the deprecated `frame_final_*`. Asserts closed-form spans, GC wiring and clamping, the
+consumed-input compositing contract, and a save/reload round-trip.
+
 </td>
 </tr>
 </table>

ROADMAP.md

@@ -97,12 +97,14 @@ Not committed; target list for the next content version. (v0.3.0 shipped the smo
 - Refresh the `slotted-actions-animation` skill against any 5.2 changes
 - Bump `blender_version_min` in the templates if 5.2 APIs are used
 - Additional snippets for asset library scripting, EXR baking, multi-file extensions
-- Gallery coverage follow-ups from the GPv3 review: light-linking, VSE sequences-to-strips witness (`grease-pencil-rosette`, `armature-bend`, `text-version-stamp`, and `image-pixels-testcard` shipped first)
+- Gallery coverage follow-ups from the GPv3 review: light-linking (`grease-pencil-rosette`, `armature-bend`, `text-version-stamp`, `image-pixels-testcard`, and `vse-cut-list` shipped first)
 - ~~UV-layer authoring witness~~ **SHIPPED** as `examples/uv-layer-grid/` — `create_grid(..., calc_uvs=True)` silent no-op without a pre-existing UV layer; closed-form UV fill + explicit assignment fallback; dual-panel render (flat texel (0,0) vs neon checker)
 - ~~Image save-format witness~~ **SHIPPED** as `examples/png-exr-alpha/` — float→PNG is RGBA16 and false-unpremultiplies as if associated-alpha (closed-form err 0.98 at RGB 0.02 / a=1/255); OpenEXR preserves float RGBA; byte→PNG is straight RGBA8; `EXR color_mode='RGB'` drops alpha
 - Attribute domain witness: writing a POINT-domain color attribute and reading it as if it were CORNER (or vice versa) silently shears colors across shared verts — companion to `color-attribute-wheel`
 - Light-linking collection witness: object light linking / receiver collections so a key illuminates only the hero (common AI miss when staging multi-light studios)
-- VSE sequences-to-strips witness: building a short cut list from `sequences.new_effect` / movie strips and asserting frame ranges survive reload
+- ~~VSE sequences-to-strips witness~~ **SHIPPED** as `examples/vse-cut-list/` — `.sequences` removed on 5.x (4.5 bridges to `.strips`), `new_effect` end kwarg `frame_end=` (4.5) vs `length=` (5.x), `frame_final_*` deprecated in favor of `left_handle`/`right_handle`/`duration`, TRANSFORM effect type removed, GAMMA_CROSS clamps to the source overlap, effect strips consume inputs only when stacked above them, same-scene scene strips render transparent; save/reload round-trip + tiny-render pixel witness
+- GAMMA_CROSS blend-curve witness: the cross blend is not the naive linear mix (mid-cross measured (0.341, 0.349, 0.463) from crimson (0.85, 0.10, 0.22) and teal (0.06, 0.75, 0.80)) — derive and assert the gamma-space closed form per frame; follow-up to `vse-cut-list`
+- Falsy `bpy_prop_collection` trap snippet: an empty collection is falsy, so `editor.strips or editor.sequences` silently falls through to the legacy accessor on an empty timeline — always branch on `hasattr`; likely generalizes across the API (found authoring `vse-cut-list`)
 
 ## Future (uncommitted)
 

docs/gallery/assets/vse-cut-list-hero.webp

@@ -198,6 +198,7 @@ <h1>Examples Gallery</h1>
     <button class="chip" data-tag="operators" type="button">operators</button>
     <button class="chip" data-tag="performance" type="button">performance</button>
     <button class="chip" data-tag="rendering" type="button">rendering</button>
+    <button class="chip" data-tag="sequencer" type="button">sequencer</button>
     <button class="chip" data-tag="shape-keys" type="button">shape-keys</button>
     <button class="chip" data-tag="transforms" type="button">transforms</button>
     <button class="chip" data-tag="uv" type="button">uv</button>
@@ -446,6 +447,17 @@ <h2><a href="uv-layer-grid/">uv-layer-grid</a></h2>
           <a class="card-link" href="uv-layer-grid/">View example <span aria-hidden="true">&rarr;</span></a>
         </div>
       </article>
+      <article class="card" data-tags="sequencer rendering">
+        <a class="card-media" href="vse-cut-list/" aria-label="vse-cut-list example detail page">
+          <img src="assets/vse-cut-list-hero.webp" alt="vse-cut-list — The sequencer API rename from 4.5 LTS to 5.x — strips (never .sequences), new_effect ending in length= vs frame_end=, and left_handle/right_handle/duration…" loading="lazy" decoding="async" />
+        </a>
+        <div class="card-body">
+          <h2><a href="vse-cut-list/">vse-cut-list</a></h2>
+          <p class="teaches">The sequencer API rename from 4.5 LTS to 5.x — strips (never .sequences), new_effect ending in length= vs frame_end=, and left_handle/right_handle/duration replacing the deprecated frame_final_*. A deterministic cut list — color programs, a clamped GAMMA_CROSS, a scene strip, a text strip — asserted before and after save/reload.</p>
+          <p class="witnesses"><span class="tag">witnesses</span> Each side hard-fails the other&#x27;s spelling: TypeError on the wrong end kwarg, AttributeError on .sequences. The cross clamps to the source overlap, effect strips consume their inputs only when stacked above them, and a same-scene scene strip renders transparent.</p>
+          <a class="card-link" href="vse-cut-list/">View example <span aria-hidden="true">&rarr;</span></a>
+        </div>
+      </article>
     </div>
   </main>
   <footer>