major: kestrel is now a tak server (#6)

## Added

- CoT (Cursor on Target) server on port 8089 enabling ATAK/iTAK device connectivity
- Support for TAK stream protocol and traditional XML CoT messages
- TLS/SSL support with automatic fallback to plain TCP
- Username/password authentication for CoT connections
- Real-time device position tracking with TTL-based expiration (90s default)
- API endpoints: `/api/cot/config`, `/api/cot/server-package`, `/api/cot/truststore`, `/api/me/cot-password`
- TAK Server section in Settings with QR code for iTAK setup
- ATAK password management in Account page for OIDC users
- CoT device markers on map showing real-time positions
- Comprehensive documentation in `docs/` directory
- Environment variables: `COT_PORT`, `COT_TTL_MS`, `COT_REQUIRE_AUTH`, `COT_SSL_CERT`, `COT_SSL_KEY`, `COT_DEBUG`
- Dependencies: `fast-xml-parser`, `jszip`, `qrcode`

## Changed

- Authentication system supports CoT password management for OIDC users
- Database schema includes `cot_password_hash` field
- Test suite refactored to follow functional design principles

## Removed

- Consolidated utility modules: `authConfig.js`, `authSkipPaths.js`, `bootstrap.js`, `poiConstants.js`, `session.js`

## Security

- XML entity expansion protection in CoT parser
- Enhanced input validation and SQL injection prevention
- Authentication timeout to prevent hanging connections

## Breaking Changes

- Port 8089 must be exposed for CoT server. Update firewall rules and Docker/Kubernetes configurations.

## Migration Notes

- OIDC users must set ATAK password via Account settings before connecting
- Docker: expose port 8089 (`-p 8089:8089`)
- Kubernetes: update Helm values to expose port 8089

Co-authored-by: Madison Grubb <madison@elastiflow.com>
Reviewed-on: #6

test/helpers/env.js

@@ -0,0 +1,54 @@
+/**
+ * Functional helpers for test environment management.
+ * Returns new objects instead of mutating process.env directly.
+ */
+
+/**
+ * Creates a new env object with specified overrides
+ * @param {Record<string, string | undefined>} overrides - Env vars to set/override
+ * @returns {Record<string, string>} New env object
+ */
+export const withEnv = overrides => ({
+  ...process.env,
+  ...Object.fromEntries(
+    Object.entries(overrides).filter(([, v]) => v !== undefined),
+  ),
+})
+
+/**
+ * Creates a new env object with specified vars removed
+ * @param {string[]} keys - Env var keys to remove
+ * @returns {Record<string, string>} New env object
+ */
+export const withoutEnv = (keys) => {
+  const result = { ...process.env }
+  for (const key of keys) {
+    delete result[key]
+  }
+  return result
+}
+
+/**
+ * Executes a function with a temporary env, restoring original after
+ * @param {Record<string, string | undefined>} env - Temporary env to use
+ * @param {() => any} fn - Function to execute
+ * @returns {any} Result of fn()
+ */
+export const withTemporaryEnv = (env, fn) => {
+  const original = { ...process.env }
+  try {
+    // Set defined values
+    Object.entries(env).forEach(([key, value]) => {
+      if (value !== undefined) {
+        process.env[key] = value
+      }
+      else {
+        delete process.env[key]
+      }
+    })
+    return fn()
+  }
+  finally {
+    process.env = original
+  }
+}