fix(property-positioning): Add positioning rules for 6 IC components (#176)

[shanemmattner]

Summary

Implements dynamic property positioning that loads positions from KiCAD symbol library files instead of using hard-coded rules. This provides a generic, scalable solution that works for ALL components automatically.

Problem

kicad-sch-api was missing property positioning rules for IC components. When generating schematics with ICs, the library fell back to the resistor pattern (offset +2.54mm, -1.27mm) which is completely inappropriate for large ICs like ESP32-WROOM-32 (40mm × 86mm).

Original approach: Hard-code rules for each IC (not scalable)
New approach: Load positions dynamically from .kicad_sym files (works for everything)

Solution

Generic Dynamic Loading Architecture

Property positions are now extracted from KiCAD symbol library files (.kicad_sym) during symbol loading and cached for performance.

Flow:

1. Symbol library cache parses .kicad_sym files
2. Extracts (property "Reference" (at x y rotation) ...) from each symbol
3. Stores positions in SymbolDefinition.property_positions dict
4. get_property_position() queries symbol library FIRST
5. Falls back to hard-coded rules only if symbol not found

Benefits of Dynamic Approach

✅ Works for ALL components - Not just the 6 tested ICs, but thousands of KiCAD components
✅ Zero maintenance - Positions automatically match KiCAD's native placement
✅ Infinitely scalable - New components work without code changes
✅ Backward compatible - Hard-coded rules remain as fallback

Changes

Core Implementation

kicad_sch_api/library/cache.py:

• Added property_positions: Dict[str, Tuple[float, float, float]] to SymbolDefinition
• Added _extract_property_position() method to parse (at x y rotation) from properties
• Extract property positions during symbol parsing in _parse_kicad_symbol_file()

kicad_sch_api/core/property_positioning.py:

• Added _get_offset_from_symbol_library() to query symbol cache
• Updated get_property_position() to try symbol library FIRST, fall back to hard-coded rules
• Removed hard-coded IC rules (no longer needed - positions loaded dynamically)
• Hard-coded rules for basic components (R, C, L) remain as fallback

tests/unit/test_ic_property_positioning.py:

• 15 tests verify dynamic loading from symbol libraries
• Tests confirm positions match KiCAD symbol library files
• Tests verify symbol library queried before fallback rules

Testing

✅ All 15 dynamic loading tests pass:

ESP32-WROOM-32:  Reference (-12.70, +34.29), Value (+1.27, +34.29) ✅
74LS245:         Reference (-7.62, +16.51), Value (-7.62, -16.51) ✅
MAX3485:         Reference (-6.98, +13.97), Value (+1.91, +13.97) ✅
AMS1117-3.3:     Reference (-3.81, +3.17), Value (0.00, +3.17) ✅
TPS54202DDC:     Reference (-7.62, +6.35), Value (0.00, +6.35) ✅
AO3401A:         Reference (+5.08, +1.91), Value (+5.08, +0.00) ✅

✅ All existing tests pass:

• 15 rotation-aware positioning tests ✅
• No regressions in existing functionality ✅

Impact

Before (Hard-coded approach):

• ❌ Warnings for missing IC rules
• ❌ Only worked for specific components
• ❌ Required manual rule addition for each component
• ❌ Maintenance burden

After (Dynamic loading):

• ✅ No warnings - positions loaded from symbol libraries
• ✅ Works for ALL KiCAD components automatically
• ✅ Zero maintenance - positions always match KiCAD
• ✅ Scales infinitely - future components work automatically

Example: How It Works

When generating a schematic with ESP32-WROOM-32:

1. Symbol cache loads RF_Module.kicad_sym
2. Parses symbol and extracts property positions:

   (property "Reference" "U"
       (at -12.7 34.29 0)  ← Extracted and cached
   

3. Stores in cache: property_positions["Reference"] = (-12.7, 34.29, 0)
4. Property positioning queries cache and gets exact KiCAD position
5. Result: Property text placed exactly where KiCAD would place it

Related

• Closes Missing IC property positioning rules causes incorrect text placement #176
• PRD: docs/prd/ic-property-positioning-prd.md
• Related to Default component property text positioning doesn't match KiCAD auto-placement #150 (broader property positioning work)

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