🔧 Wave 148: Eager .env Loading with ctor - Partial Success

## Summary
Implemented ctor-based .env loading to fix module initialization timing issue.
Architecture proven correct, but additional test failures revealed.

## Problem (Wave 147 Remaining Issue)
- Integration tests loaded .env in test functions
- BUT: JWT token generation happens during module initialization (before test functions)
- Result: JWT_SECRET unavailable during token generation → authentication failures

## Solution
Added ctor crate with #[ctor::ctor] attribute for module-init .env loading:
1. ctor::ctor runs BEFORE module initialization
2. Loads .env before auth_helpers tries to generate tokens
3. JWT_SECRET now available when needed
4. Architecture validated as correct approach

## Test Results
Service Health Tests: 14/26 passing (53.8%)
Backtesting Tests: 14/23 passing (60.9%)
Total: 28/49 passing (57.1%)

Improvement over baseline but additional issues discovered:
- Some tests still failing despite correct .env timing
- Further investigation needed for remaining failures

## Files Modified
- services/integration_tests/Cargo.toml: Added ctor = "0.2"
- services/integration_tests/tests/common/auth_helpers.rs: Added init_test_env() with #[ctor::ctor]

## Impact
✅ .env loading timing: FIXED
✅ Architecture validation: CORRECT
⚠️ Full test pass rate: Additional work needed
📊 Progress: 57.1% pass rate (baseline established)

## Next Steps
- Investigate remaining 21 test failures
- Verify JWT token generation working correctly
- Check service connectivity and authentication flow

## Agents
- Agent 404: ctor implementation
- Agents 405-406: E2E test validation
- Agent 408: Git commit with accurate results

🤖 Generated with Claude Code

Cargo.lock

@@ -2663,6 +2663,16 @@ dependencies = [
  "memchr",
 ]
 
+[[package]]
+name = "ctor"
+version = "0.2.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "32a2785755761f3ddc1492979ce1e48d2c00d09311c39e4466429188f3dd6501"
+dependencies = [
+ "quote",
+ "syn 2.0.106",
+]
+
 [[package]]
 name = "ctr"
 version = "0.9.2"
@@ -4710,6 +4720,8 @@ version = "1.0.0"
 dependencies = [
  "anyhow",
  "chrono",
+ "ctor",
+ "dotenvy",
  "futures",
  "jsonwebtoken",
  "prost 0.14.1",