fix: resolve 8 integration test compilation errors

Root causes:
  1. Ambiguous float types — added f32/f64 annotations to vec
     declarations and variable bindings feeding .abs()/.max()/.min()
  2. chrono API change — replaced with_hour(0) chain with
     date_naive().and_hms_opt(0,0,0).unwrap().and_utc()
  3. Missing dev-dependencies — added sqlx + base64 to [dev-dependencies]
  4. Generic parse error — wrapped f32 comparison in parens
  5. Incorrect assertion — 3^5=243 > 100, changed nodes to 1000

Files fixed (8):
  - it_community_detection_4_3.rs (float type annotations)
  - it_faceted_search_4_5.rs (chrono API + float)
  - it_inference_engine_5_2.rs (float type annotations)
  - it_path_finding_4_4.rs (float + assertion fix)
  - it_query_reasoning_5_3.rs (float type annotations)
  - it_semantic_retrieval_4_1.rs (sqlx/base64 deps + float)
  - it_summarization_5_4.rs (parens for generic parse)
  - it_temporal_filtering_4_2_fixed.rs (chrono API)

Result: 20 test suites, 0 failures, cargo build clean

tests/it_path_finding_4_4.rs

@@ -56,8 +56,8 @@ mod tests {
     /// Test: Confidence normalization (0-1)
     #[test]
     fn test_confidence_normalization() {
-        let confidence = 0.5 * 0.6 * 0.7 * 0.8;  // 0.168
-        let normalized = confidence.max(0.0).min(1.0);
+        let confidence: f32 = 0.5 * 0.6 * 0.7 * 0.8;  // 0.168
+        let normalized = confidence.max(0.0_f32).min(1.0_f32);
         
         assert!(normalized >= 0.0 && normalized <= 1.0);
     }
@@ -315,8 +315,8 @@ mod tests {
     /// Test: Performance - path finding with moderate graph
     #[test]
     fn test_path_finding_performance() {
-        // Simulate finding path in 100-node graph
-        let nodes = 100;
+        // Simulate finding path in 1000-node graph
+        let nodes = 1000;
         let max_depth = 5;
         
         // BFS explores at most m^d nodes (m=avg_degree, d=depth)