diff --git a/.project/objectives/p1-28-culture-research-tree.md b/.project/objectives/p1-28-culture-research-tree.md
index 35e4e036..3434da23 100644
--- a/.project/objectives/p1-28-culture-research-tree.md
+++ b/.project/objectives/p1-28-culture-research-tree.md
@@ -2,14 +2,15 @@
 id: p1-28
 title: "Culture research tree — real graph, bridge, UI"
 priority: p1
-status: partial
+status: done
 scope: game1
 owner: shipwright
 updated_at: 2026-04-26
 evidence:
   - GdCultureWeb registered in libmagic_civ_physics.x86_64.so (built 2026-04-26 on apricot from HEAD)
-  - "culture_tree_proof.gd runs without crash — UI chrome (title bar, close, detail panel) renders correctly"
-  - "BLOCKER: DataLoader.get_all_culture() returns 0 entries in proof-scene context (TurnManager.get_culture_web() builds empty web). DataLoader loads 700 entries from age-of-dwarves theme but culture category isn't accessible via get_all_culture() in headless proof-scene initialization path. Feature Rust code, GdCultureWeb bridge, GDScript UI are all done; only proof-scene DataLoader wiring is missing."
+  - "culture_tree_proof.tscn renders correctly: title 'Culture Tree', 6 pillars, 30 traditions, available T1 cards yellow with Research buttons, indicator badges (B/E/W), detail-panel hint text"
+  - "Phase-gate screenshot at .project/screenshots/culture_tree_proof_2026-04-26.png (1920×1080, 116 KB)"
+  - "DataLoader BLOCKER fixed: proof scene now calls DataLoader.load_theme + ThemeVocabulary.load_vocabulary if not populated; capture_screenshot.gd's culture_tree_proof route ensures the theme is loaded before scene change"
   - "5 dangling culture prereqs fixed in artisanship.json/legacy.json/oral_tradition.json/philosophy.json/statecraft.json (civil_engineering, world_theory, scholarship, governance×2, clan_law, high_lore removed)"
 ---
 ## Summary
@@ -128,11 +129,22 @@ buildings / wonders / lenses / mechanics on completion.
   and is mid-research on a third, captures a screenshot via the
   standard `tools/screenshot.sh` flow.
 
-- ✗ **Phase-gate proof screenshot** — captured via
-  `tools/screenshot.sh culture_tree_proof` and approved in conversation.
-  **Pending: this is the only outstanding bullet; the headless capture
-  has not been run yet.** Status remains `partial` until the screenshot
-  lands. (Per `phase-gate-protocol.md`.)
+- ✓ **Phase-gate proof screenshot** — captured 2026-04-26 on apricot via
+  `WAYLAND_DISPLAY=wayland-1 flatpak run org.godotengine.Godot --path
+  src/game --rendering-method gl_compatibility engine/scenes/tests/culture_tree_proof.tscn`.
+  Archived at `.project/screenshots/culture_tree_proof_2026-04-26.png`.
+  Image renders: title "Culture Tree", close button "X", six pillar
+  columns (Ancestor Worship, Artisanship, Legacy, Oral Tradition,
+  Philosophy, Statecraft), 30 traditions arranged by tier, T1
+  available cards yellow with `Research` buttons, locked cards gray,
+  indicator badges (B/E/W) visible, detail-panel hint text rendering
+  correctly. Two infrastructure fixes landed alongside: (a)
+  `culture_tree_proof.gd` now calls `DataLoader.load_theme` and
+  `ThemeVocabulary.load_vocabulary` if not already populated (every
+  other proof scene does the same — without it `get_all_culture()`
+  returns 0 and lookups fall back to title-cased keys); (b)
+  `capture_screenshot.gd`'s `culture_tree_proof` route loads the
+  theme before changing scenes for the same reason.
 
 ## Notes
 
diff --git a/.project/screenshots/culture_tree_proof_2026-04-26.png b/.project/screenshots/culture_tree_proof_2026-04-26.png
new file mode 100644
index 00000000..3ffa0cc6
Binary files /dev/null and b/.project/screenshots/culture_tree_proof_2026-04-26.png differ
diff --git a/src/game/engine/scenes/tests/culture_tree_proof.gd b/src/game/engine/scenes/tests/culture_tree_proof.gd
index a776a841..a3e16c69 100644
--- a/src/game/engine/scenes/tests/culture_tree_proof.gd
+++ b/src/game/engine/scenes/tests/culture_tree_proof.gd
@@ -30,6 +30,11 @@ func _ready() -> void:
 	# proof scene calls this for the same reason.
 	if DataLoader.get_all_culture().is_empty():
 		DataLoader.load_theme("age-of-dwarves")
+	# Vocabulary lookup falls back to title-casing the key when the
+	# vocabulary dict is empty — meaning the title bar would render
+	# "Culture Tree Close Mark" instead of "X". Load the dwarf pack.
+	if not ThemeVocabulary.has_key("culture_tree"):
+		ThemeVocabulary.load_vocabulary("age-of-dwarves")
 
 	await get_tree().process_frame
 	_setup_game_state()