[feat](trx-frontend-http): implement HTTP authentication (phases 1-3)

Add optional passphrase-based authentication with two roles (rx/control),
session management, auth middleware, and protected routes.

Phase 1: Config model with HttpAuthConfig struct, CookieSameSite enum,
validation logic for enabled auth requiring at least one passphrase.

Phase 2: Auth module with:
- AuthRole enum (Rx, Control)
- SessionRecord and SessionStore for in-memory session management
- AuthConfig at runtime
- /auth/login, /auth/logout, /auth/session endpoints
- Constant-time passphrase comparison for timing attack mitigation

Phase 3: Integration with:
- AuthMiddleware for route protection with public/read/control classification
- Server-side AuthState setup with cleanup task for expired sessions
- Auth endpoints registered in api.rs configure()

Sessions use 128-bit random IDs (hex-encoded), HttpOnly cookies, configurable
SameSite attribute. Auth is disabled by default to preserve current behavior.

All unit and integration tests passing.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Signed-off-by: Stanislaw Grams <stanislawgrams@gmail.com>

Cargo.lock

@@ -49,7 +49,7 @@ dependencies = [
  "mime",
  "percent-encoding",
  "pin-project-lite",
- "rand",
+ "rand 0.9.2",
  "sha1",
  "smallvec",
  "tokio",
@@ -942,6 +942,12 @@ version = "0.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2304e00983f87ffb38b55b444b5e3b60a884b5d30c0fca7d82fe33449bbe55ea"
 
+[[package]]
+name = "hex"
+version = "0.4.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7f24254aa9a54b5c858eaee2f5bccdb46aaf0e486a595ed5fd8f86ba55232a70"
+
 [[package]]
 name = "http"
 version = "0.2.12"
@@ -1561,14 +1567,35 @@ version = "5.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "69cdb34c158ceb288df11e18b4bd39de994f6657d83847bdffdbd7f346754b0f"
 
+[[package]]
+name = "rand"
+version = "0.8.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "34af8d1a0e25924bc5b7c43c079c942339d8f0a8b57c39049bef581b46327404"
+dependencies = [
+ "libc",
+ "rand_chacha 0.3.1",
+ "rand_core 0.6.4",
+]
+
 [[package]]
 name = "rand"
 version = "0.9.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6db2770f06117d490610c7488547d543617b21bfa07796d7a12f6f1bd53850d1"
 dependencies = [
- "rand_chacha",
- "rand_core",
+ "rand_chacha 0.9.0",
+ "rand_core 0.9.3",
+]
+
+[[package]]
+name = "rand_chacha"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e6c10a63a0fa32252be49d21e7709d4d4baf8d231c2dbce1eaa8141b9b127d88"
+dependencies = [
+ "ppv-lite86",
+ "rand_core 0.6.4",
 ]
 
 [[package]]
@@ -1578,7 +1605,16 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d3022b5f1df60f26e1ffddd6c66e8aa15de382ae63b3a0c1bfc0e4d3e3f325cb"
 dependencies = [
  "ppv-lite86",
- "rand_core",
+ "rand_core 0.9.3",
+]
+
+[[package]]
+name = "rand_core"
+version = "0.6.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ec0be4795e2f6a28069bec0b5ff3e2ac9bafc99e6a9a7dc3547996c5c816922c"
+dependencies = [
+ "getrandom 0.2.17",
 ]
 
 [[package]]
@@ -2266,6 +2302,8 @@ dependencies = [
  "actix-ws",
  "bytes",
  "futures-util",
+ "hex",
+ "rand 0.8.5",
  "serde",
  "serde_json",
  "tokio",