Stabilize core correctness and sync project plan state

src/atocore/context/project_state.py

@@ -12,10 +12,8 @@ Project state is manually curated or explicitly confirmed facts about a project.
 It always wins over retrieval-based context when there's a conflict.
 """
 
-import json
-import time
 import uuid
-from dataclasses import dataclass, field
+from dataclasses import dataclass
 from datetime import datetime, timezone
 
 from atocore.models.database import get_connection
@@ -81,7 +79,7 @@ def ensure_project(name: str, description: str = "") -> str:
     """Get or create a project by name. Returns project_id."""
     with get_connection() as conn:
         row = conn.execute(
-            "SELECT id FROM projects WHERE name = ?", (name,)
+            "SELECT id FROM projects WHERE lower(name) = lower(?)", (name,)
         ).fetchone()
         if row:
             return row["id"]
@@ -106,6 +104,7 @@ def set_state(
     """Set or update a project state entry. Upsert semantics."""
     if category not in CATEGORIES:
         raise ValueError(f"Invalid category '{category}'. Must be one of: {CATEGORIES}")
+    _validate_confidence(confidence)
 
     project_id = ensure_project(project_name)
     entry_id = str(uuid.uuid4())
@@ -157,7 +156,7 @@ def get_state(
     """Get project state entries, optionally filtered by category."""
     with get_connection() as conn:
         project = conn.execute(
-            "SELECT id FROM projects WHERE name = ?", (project_name,)
+            "SELECT id FROM projects WHERE lower(name) = lower(?)", (project_name,)
         ).fetchone()
         if not project:
             return []
@@ -195,7 +194,7 @@ def invalidate_state(project_name: str, category: str, key: str) -> bool:
     """Mark a project state entry as superseded."""
     with get_connection() as conn:
         project = conn.execute(
-            "SELECT id FROM projects WHERE name = ?", (project_name,)
+            "SELECT id FROM projects WHERE lower(name) = lower(?)", (project_name,)
         ).fetchone()
         if not project:
             return False
@@ -229,3 +228,8 @@ def format_project_state(entries: list[ProjectStateEntry]) -> str:
 
     lines.append("\n--- End Project State ---")
     return "\n".join(lines)
+
+
+def _validate_confidence(confidence: float) -> None:
+    if not 0.0 <= confidence <= 1.0:
+        raise ValueError("Confidence must be between 0.0 and 1.0")