docs: number all tasks for reference

Assigned reference numbers to all remaining tasks in documentation:
- Task #34: Full STL Removal
- Task #35: CRT Replacement
- Task #36: Blender Exporter
- Task #37: Asset Ingestion
- Task #38: Runtime Loader
- Task #39: Visual Debugging System
- Task #40: Advanced Lighting & Transparency
- Task #41: Spectrogram Editor HTML Tool
- Task #42: Vectorial Spectrogram Reader (C++)
- Task #43: Spectrogram Drawing Bricks

Ensured consistent task numbering across PROJECT_CONTEXT.md and TODO.md.

1 files changed, 3 insertions, 3 deletions

diff --git a/doc/3D.md b/doc/3D.md
index e944cbe..5c5d1bd 100644
--- a/doc/3D.md
+++ b/doc/3D.md
@@ -35,16 +35,16 @@ removed with STRIP_ALL) that:
    d) displays the ray/object intersection interactively
    e) show the lights (direction, cone, ...), display their shadow-map in 3d and on-screen (2d).
 
-This must be captured and tracked as a sub-task
+This must be captured and tracked as **Task #39: Visual Debugging System**.
 
 
 ## future step
 
 Have an exporter from Blender modelling software. That would be a converter
 from simple blender-exported files to our internal format (as an asset for
-our AssetManager or as c++ code directly)
+our AssetManager or as c++ code directly) - **Task #36: Blender Exporter**.
 
 ## latter improvement
 
 How to handle transparency? Multi-Ray-casting?
-We need to think about the lighting strategy.
+We need to think about the lighting strategy. - **Task #40: Advanced Lighting & Transparency**.