fix: resolve 8 integration test compilation errors (#46)

## Problem
8 integration test files failed to compile due to:
1. Ambiguous float types (Rust 2024+ stricter inference)
2. chrono 0.4 API change (`with_hour` removed)
3. Missing `sqlx` + `base64` in `[dev-dependencies]`
4. `<` parsed as generics instead of comparison
5. Incorrect assertion (3^5=243 > 100)

## Fix
- Added `f32`/`f64` type annotations to vec declarations and bindings
- Replaced `with_hour(0)` with `date_naive().and_hms_opt(0,0,0).unwrap().and_utc()`
- Added `sqlx` + `base64` to `[dev-dependencies]`
- Wrapped comparison in parens
- Fixed assertion: nodes=100 → nodes=1000

## Validation
- `cargo build --release` clean
- `cargo test` — 20 test suites, 0 failures
- 10 files changed, 46 insertions, 42 deletionsReviewed-on: #46

Co-authored-by: rock <[email protected]>

tests/it_faceted_search_4_5.rs

@@ -17,7 +17,7 @@ mod tests {
         let percentage = (count as f32 / total as f32) * 100.0;
 
         assert_eq!(count, 42);
-        assert!((percentage - 42.0).abs() < 0.01);
+        assert!((percentage - 42.0_f32).abs() < 0.01);
     }
 
     /// Test: Confidence level "high" (0.8+)
@@ -52,7 +52,7 @@ mod tests {
     #[test]
     fn test_date_range_today() {
         let now = chrono::Utc::now();
-        let start_of_day = now.with_hour(0).unwrap().with_minute(0).unwrap().with_second(0).unwrap();
+        let start_of_day = now.date_naive().and_hms_opt(0, 0, 0).unwrap().and_utc();
 
         assert!(now >= start_of_day);
     }
@@ -199,7 +199,7 @@ mod tests {
         let total = 100;
         let percentage = (count as f32 / total as f32) * 100.0;
         
-        assert!((percentage - 30.0).abs() < 0.01);
+        assert!((percentage - 30.0_f32).abs() < 0.01);
     }
 
     /// Test: Facet percentage with rounding
@@ -209,7 +209,7 @@ mod tests {
         let total = 100;
         let percentage = (count as f32 / total as f32) * 100.0;
         
-        assert!((percentage - 33.0).abs() < 0.01);
+        assert!((percentage - 33.0_f32).abs() < 0.01);
     }
 
     /// Test: Zero total in percentage (edge case)