Add bounded family evolution workflow

[epowell40]

What changed

• adds public plan/apply/readback endpoints for bounded loaded-family evolution
• creates a cloned family and new type with exact width/depth values
• adds optional light dashed symbolic clearance geometry on an explicit or power-connector-resolved side
• requires immutable target identity, hash-bound plans, family-content fingerprints, typed confirmation, and guarded workspace artifacts
• verifies symbolic geometry/style readback and project rollback state

Why

Engineers commonly begin with generic equipment and later need to update a selected unit’s family/type size and documented service clearance without altering every existing instance of the source family.

Validation

• public common suite: 201 passed, 0 failed
• RevitBridge net48 build: 0 errors
• live Revit 2024 Snowdon test copy: HRU403 changed to 3 ft 8 in x 4 ft 2 in
• live readback: four symbolic curves, Operator - Clearance Dash, line weight 1, RGB 160/160/160
• visual L4 verification: 36-inch clearance appears on the electrical-connector/right side

The source family remains unchanged; the evolved RFA is retained under the guarded local workspace.