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_inference_engine_5_2.rs

@@ -126,11 +126,11 @@ mod tests {
     /// Test: Reasoning path confidence
     #[test]
     fn test_reasoning_path_confidence() {
-        let conf1 = 0.9;
+        let conf1: f64 = 0.9;
         let conf2 = 0.9;
         let total = conf1 * conf2;
         
-        assert!((total - 0.81).abs() < 0.01);
+        assert!((total - 0.81_f64).abs() < 0.01);
     }
 
     /// Test: Max hops validation
@@ -172,17 +172,17 @@ mod tests {
     /// Test: Confidence chaining (product)
     #[test]
     fn test_confidence_chaining_product() {
-        let c1 = 0.9;
+        let c1: f64 = 0.9;
         let c2 = 0.85;
         let result = c1 * c2;
         
-        assert!((result - 0.765).abs() < 0.01);
+        assert!((result - 0.765_f64).abs() < 0.01);
     }
 
     /// Test: Confidence bounded to 1.0
     #[test]
     fn test_confidence_bounded() {
-        let conf = 1.2;
+        let conf: f64 = 1.2;
         let bounded = conf.min(1.0);
         
         assert_eq!(bounded, 1.0);