Docs: reduce over-documentation across gameplay scripts

Trim restated narration, dead commented-out code, and oversized class
headers; keep all why-comments (authority, timing, edge cases), tooltips,
and serialization caveats.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Assets/Scripts/MeshPainter.Undo.cs

@@ -8,21 +8,17 @@ public partial class MeshPainter
 {
     // --- Undo / redo: per-stroke history of the canonical maps, mirrored on every peer ---
     //
-    // One stroke (mouse-down -> mouse-up) = one undo step. Each entry is the full canonical map set AFTER
-    // that edit, restored by re-seeding the backend (same path as load / late-join snapshot). The baseline
-    // at index 0 is the material seed (or a loaded / snapshotted baseline).
+    // One stroke (mouse-down -> mouse-up) = one undo step; each entry is the full canonical map set AFTER
+    // that edit, restored by re-seeding the backend. Index 0 is the baseline (material seed, or a
+    // loaded/snapshotted one).
     //
-    // Networked design: every replica keeps the SAME history, so undo/redo replicates as a tiny command
-    // instead of re-broadcasting the whole painting. The owner assigns each committed stroke a monotonic
-    // CHECKPOINT ID; remotes replay the same stamps and capture history at the same boundaries (driven by a
-    // network checkpoint marker) under the owner's id. Undo/redo carries the TARGET id; a peer that holds
-    // that id restores locally, a peer that doesn't (a late joiner asked to undo past its join) falls back
-    // to a snapshot. PlayerPaintSync drives all of this through OnHistoryCheckpoint / OnHistoryRestore.
+    // Networked: every replica keeps the SAME history, so undo/redo replicates as a tiny command. The
+    // owner tags each committed stroke with a monotonic CHECKPOINT ID; remotes capture history at the same
+    // boundaries under that id. Undo/redo carries the TARGET id; a peer lacking it (a late joiner) falls
+    // back to a snapshot. PlayerPaintSync drives this via OnHistoryCheckpoint / OnHistoryRestore.
     //
-    // Memory: consecutive states differ only in the maps a stroke actually painted, so unchanged maps are
-    // shared by reference with the previous entry (copy-on-write). This is safe because both backends
-    // CLONE their seed input (SeedCpuPixels / SeedGpuMap) and ReadCanonical returns fresh arrays - nothing
-    // ever writes back into a stored state array.
+    // Memory: unchanged maps are shared by reference with the previous entry (copy-on-write) - safe
+    // because both backends CLONE their seed input and ReadCanonical returns fresh arrays.
 
     [Header("Undo")]
     [Tooltip("Maximum number of undoable edits kept in memory (strokes + loads). Older edits drop off; " +