Add kaya-otel package for OpenTelemetry tracing and metrics

Instrument HTTP requests and WebSocket connections via Kaya hooks, covering both ASGI and RSGI. Records handler exceptions, WebSocket close codes, optional header capture, exclusions and lifecycle hooks.

Add route-template resolution and exception visibility to kaya-core so trace/metric attributes can use low-cardinality routes and failed spans can record escaped exceptions.

README.md

@@ -15,6 +15,7 @@ This repository is a monorepo for the Kaya framework. The code is split into ind
 - **kaya-openapi** — automatic OpenAPI specification generation (`packages/kaya-openapi/`)
 - **kaya-cors** — CORS (Cross-Origin Resource Sharing) support (`packages/kaya-cors/`)
 - **kaya-forwarded** — trusted-proxy `Forwarded`/`X-Forwarded-*` client address resolution (`packages/kaya-forwarded/`)
+- **kaya-otel** — OpenTelemetry tracing and metrics (`packages/kaya-otel/`)
 
 Additional `kaya-*` packages can be added as new directories under `packages/`.
 
@@ -29,7 +30,7 @@ pip install --index-url https://gitea.woggioni.net/api/packages/woggioni/pypi/si
 Install the packages in development mode:
 
 ```bash
-pip install -e packages/kaya-core -e packages/kaya-rsgi -e packages/kaya-session -e packages/kaya-session-redis -e packages/kaya-session-memcache -e packages/kaya-oidc -e packages/kaya-openapi -e packages/kaya-cors -e packages/kaya-forwarded
+pip install -e packages/kaya-core -e packages/kaya-rsgi -e packages/kaya-session -e packages/kaya-session-redis -e packages/kaya-session-memcache -e packages/kaya-oidc -e packages/kaya-openapi -e packages/kaya-cors -e packages/kaya-forwarded -e packages/kaya-otel
 ```
 
 Run the example:
@@ -50,6 +51,7 @@ python -m unittest discover -s packages/kaya-oidc/tests
 python -m unittest discover -s packages/kaya-openapi/tests
 python -m unittest discover -s packages/kaya-cors/tests
 python -m unittest discover -s packages/kaya-forwarded/tests
+python -m unittest discover -s packages/kaya-otel/tests
 ```
 
 ## Static analysis
@@ -64,6 +66,7 @@ mypy -p kaya.oidc
 mypy -p kaya.openapi
 mypy -p kaya.cors
 mypy -p kaya.forwarded
+mypy -p kaya.otel
 ```
 
 ## Building packages
@@ -78,4 +81,5 @@ python -m build packages/kaya-oidc
 python -m build packages/kaya-openapi
 python -m build packages/kaya-cors
 python -m build packages/kaya-forwarded
+python -m build packages/kaya-otel
 ```