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]>

crates/mem-ingest/src/authentik_jwt.rs

@@ -136,13 +136,13 @@ mod tests {
             access_token: "test".to_string(),
             token_type: "Bearer".to_string(),
             expires_in: 3600,
-            obtained_at: SystemTime::now(),
+            obtained_at: Some(SystemTime::now()),
         };
 
         assert!(!token.is_expired());
 
         // Simulate aged token
-        token.obtained_at = SystemTime::now() - Duration::from_secs(3600);
+        token.obtained_at = Some(SystemTime::now() - Duration::from_secs(3600));
         assert!(token.is_expired());
     }