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_summarization_5_4.rs

@@ -308,7 +308,7 @@ mod tests {
         let unique_words = 15;
         let total_words = 20;
         
-        assert!(unique_words as f32 / total_words as f32 < 1.0);
+        assert!((unique_words as f32 / total_words as f32) < 1.0);
     }
 
     /// Test: Key fact count limit
@@ -337,7 +337,7 @@ mod tests {
         let c3 = 0.7;
         let avg = (c1 + c2 + c3) / 3.0;
         
-        assert!((avg - 0.8).abs() < 0.1);
+        assert!((avg - 0.8_f32).abs() < 0.1);
     }
 
     /// Test: Content length calculation