refactor: remove session auth, add DbType enum, native async broker

- Remove `auth`, `sessions-db` features and all tower-sessions/tower-sessions-sqlx-store deps
- Delete `src/session.rs` (InfraSessionStore)
- `ServerConfig`: remove `session_secret` field and `attach_session_layer()` helper
- `db.rs`: add explicit `DbType` enum to `DatabaseConfig`; `connect()` now matches on
  `db_type` instead of sniffing URL prefixes; remove `connect_sqlite()` standalone fn
- `broker/mod.rs`: replace `#[async_trait]` with native async fn (Rust 2024 AFIT)
- `broker/nats.rs`: remove `#[async_trait]` to match trait definition
- `ai/embeddings.rs`: remove sync `generate_embedding()` (wasteful thread spawn);
  keep only `generate_embedding_async()` as the public API
- Default features: `["logging", "db-sqlx", "auth", "http"]` → `["logging"]`
- Bump version to 0.1.11

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Cargo.lock

@@ -533,17 +533,6 @@ version = "0.9.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c2459377285ad874054d797f3ccebf984978aa39129f6eafde5cdc8315b612f8"
 
-[[package]]
-name = "cookie"
-version = "0.18.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4ddef33a339a91ea89fb53151bd0a4689cfce27055c291dfa69945475d22c747"
-dependencies = [
- "percent-encoding",
- "time",
- "version_check",
-]
-
 [[package]]
 name = "core-foundation"
 version = "0.9.4"
@@ -1775,7 +1764,7 @@ dependencies = [
 
 [[package]]
 name = "k-core"
-version = "0.1.10"
+version = "0.1.11"
 dependencies = [
  "anyhow",
  "async-nats",
@@ -1789,12 +1778,9 @@ dependencies = [
  "serde",
  "sqlx",
  "thiserror 2.0.17",
- "time",
  "tokio",
  "tower 0.5.2",
  "tower-http",
- "tower-sessions",
- "tower-sessions-sqlx-store",
  "tracing",
  "tracing-subscriber",
  "uuid",
@@ -1878,7 +1864,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "224399e74b87b5f3557511d98dff8b14089b3dadafcab6bb93eab67d3aace965"
 dependencies = [
  "scopeguard",
- "serde",
 ]
 
 [[package]]
@@ -2958,25 +2943,6 @@ dependencies = [
  "windows-sys 0.52.0",
 ]
 
-[[package]]
-name = "rmp"
-version = "0.8.15"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4ba8be72d372b2c9b35542551678538b562e7cf86c3315773cae48dfbfe7790c"
-dependencies = [
- "num-traits",
-]
-
-[[package]]
-name = "rmp-serde"
-version = "1.3.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "72f81bee8c8ef9b577d1681a70ebbc962c232461e397b22c208c43c04b67a155"
-dependencies = [
- "rmp",
- "serde",
-]
-
 [[package]]
 name = "rsa"
 version = "0.9.9"
@@ -3479,7 +3445,6 @@ dependencies = [
  "sha2",
  "smallvec 1.15.1",
  "thiserror 2.0.17",
- "time",
  "tokio",
  "tokio-stream",
  "tracing",
@@ -3564,7 +3529,6 @@ dependencies = [
  "sqlx-core",
  "stringprep",
  "thiserror 2.0.17",
- "time",
  "tracing",
  "uuid",
  "whoami",
@@ -3604,7 +3568,6 @@ dependencies = [
  "sqlx-core",
  "stringprep",
  "thiserror 2.0.17",
- "time",
  "tracing",
  "uuid",
  "whoami",
@@ -3631,7 +3594,6 @@ dependencies = [
  "serde_urlencoded",
  "sqlx-core",
  "thiserror 2.0.17",
- "time",
  "tracing",
  "url",
  "uuid",
@@ -4063,22 +4025,6 @@ dependencies = [
  "tracing",
 ]
 
-[[package]]
-name = "tower-cookies"
-version = "0.11.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "151b5a3e3c45df17466454bb74e9ecedecc955269bdedbf4d150dfa393b55a36"
-dependencies = [
- "axum-core 0.5.6",
- "cookie",
- "futures-util",
- "http",
- "parking_lot",
- "pin-project-lite",
- "tower-layer",
- "tower-service",
-]
-
 [[package]]
 name = "tower-http"
 version = "0.6.8"
@@ -4110,71 +4056,6 @@ version = "0.3.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8df9b6e13f2d32c91b9bd719c00d1958837bc7dec474d94952798cc8e69eeec3"
 
-[[package]]
-name = "tower-sessions"
-version = "0.14.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "43a05911f23e8fae446005fe9b7b97e66d95b6db589dc1c4d59f6a2d4d4927d3"
-dependencies = [
- "async-trait",
- "http",
- "time",
- "tokio",
- "tower-cookies",
- "tower-layer",
- "tower-service",
- "tower-sessions-core",
- "tower-sessions-memory-store",
- "tracing",
-]
-
-[[package]]
-name = "tower-sessions-core"
-version = "0.14.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ce8cce604865576b7751b7a6bc3058f754569a60d689328bb74c52b1d87e355b"
-dependencies = [
- "async-trait",
- "axum-core 0.5.6",
- "base64 0.22.1",
- "futures",
- "http",
- "parking_lot",
- "rand 0.8.5",
- "serde",
- "serde_json",
- "thiserror 2.0.17",
- "time",
- "tokio",
- "tracing",
-]
-
-[[package]]
-name = "tower-sessions-memory-store"
-version = "0.14.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fb05909f2e1420135a831dd5df9f5596d69196d0a64c3499ca474c4bd3d33242"
-dependencies = [
- "async-trait",
- "time",
- "tokio",
- "tower-sessions-core",
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-
-[[package]]
-name = "tower-sessions-sqlx-store"
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-source = "registry+https://github.com/rust-lang/crates.io-index"
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-dependencies = [
- "async-trait",
- "rmp-serde",
- "sqlx",
- "thiserror 1.0.69",
- "time",
- "tower-sessions-core",
-]
-
 [[package]]
 name = "tracing"
 version = "0.1.44"