feat(memory): add procedural memory implementation (Issue #92)

Implements procedural memory for learned skills and procedures:

Core functionality:
- ProceduralMemory class for procedure storage/retrieval
- record_procedure with duplicate detection and step merging
- find_matching for context-based procedure search
- record_outcome for success/failure tracking
- get_best_procedure for finding highest success rate
- update_steps for procedure refinement

Supporting modules:
- ProcedureMatcher: Keyword-based procedure matching
- MatchResult/MatchContext: Matching result types
- Success rate weighting in match scoring

Test coverage:
- 43 unit tests covering all modules
- matching.py: 97% coverage
- memory.py: 86% coverage

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/app/services/memory/procedural/__init__.py

@@ -1,7 +1,22 @@
+# app/services/memory/procedural/__init__.py
 """
 Procedural Memory
 
 Learned skills and procedures from successful task patterns.
 """
 
-# Will be populated in #92
+from .matching import (
+    MatchContext,
+    MatchResult,
+    ProcedureMatcher,
+    get_procedure_matcher,
+)
+from .memory import ProceduralMemory
+
+__all__ = [
+    "MatchContext",
+    "MatchResult",
+    "ProceduralMemory",
+    "ProcedureMatcher",
+    "get_procedure_matcher",
+]