Fix duplicate prefix numbers in user guide notebooks

[brendancol]

Closes #1076

Summary

• Notebooks 33, 34, and 35 each had multiple files sharing the same prefix (35 had seven). Renumbered from 33 onward so every notebook gets a unique sequential integer (0-45).
• Pure file renames, no content changes.

Rename mapping (33+ only, 0-32 unchanged)

Old prefix	New prefix	Notebook
33	33	Porto_Taxi_Trajectories (unchanged)
33	34	Vegetation_Flood_Modeling
34	35	Normalization
34	36	Reproject
35	37	Edge_Detection
35	38	Focal_Variety
35	39	GeoTIFF_IO
35	40	JPEG2000_Compression
35	41	MCDA
35	42	Northness_Eastness
35	43	Spectral_Indices
36	44	Rechunk_No_Shuffle
37	45	Fused_Overlap

Test plan

• Verified zero duplicate prefixes remain
• Verified 46 notebooks total (0-45)
• Checked no cross-references to old filenames inside notebooks