refactor: comprehensive audit — fix bugs, harden security, deduplicate providers, add CI/Docker

Phase 1: Fix compilation (config_path Option<PathBuf>, streaming test, stale test cleanup)
Phase 2: Fix critical bugs (remove block_on deadlocks in 4 providers, fix broken SQL query builder)
Phase 3: Security hardening (session manager, real auth, token masking, Gemini key to header, password policy)
Phase 4: Implement stubs (real provider test, /proc health metrics, client/provider/backup endpoints, has_images)
Phase 5: Code quality (shared provider helpers, explicit re-exports, all Clippy warnings fixed, unwrap removal, 6 unused deps removed, dashboard split into 7 sub-modules)
Phase 6: Infrastructure (GitHub Actions CI, multi-stage Dockerfile, rustfmt.toml, clippy.toml, script fixes)

Cargo.toml

@@ -16,7 +16,6 @@ tower-http = { version = "0.6", features = ["trace", "cors", "compression-gzip",
 
 # ========== HTTP Clients ==========
 reqwest = { version = "0.12", default-features = false, features = ["json", "stream", "rustls-tls"] }
-async-openai = { version = "0.33", default-features = false, features = ["_api", "chat-completion"] }
 tiktoken-rs = "0.9"
 
 # ========== Database & ORM ==========
@@ -41,7 +40,6 @@ tracing-subscriber = { version = "0.3", features = ["env-filter", "json"] }
 base64 = "0.21"
 image = { version = "0.25", default-features = false, features = ["jpeg", "png", "webp"] }
 mime = "0.3"
-mime_guess = "2.0"
 
 # ========== Error Handling & Utilities ==========
 anyhow = "1.0"
@@ -53,12 +51,6 @@ futures = "0.3"
 async-trait = "0.1"
 async-stream = "0.3"
 reqwest-eventsource = "0.6"
-once_cell = "1.19"
-regex = "1.10"
-rand = "0.8"
-
-# ========== Rate Limiting & Circuit Breaking ==========
-governor = "0.6"
 
 [dev-dependencies]
 tokio-test = "0.4"