chore: add selective CI, SemVer changelog and update dependencies

[egorsmkv]

Add selective CI for relevant pull requests, pushes to master, and manual runs. Path filters skip documentation-only changes; concurrency cancels superseded runs. Quality checks run formatting, locked cargo check and pedantic Clippy with warnings denied. Test jobs run Rust regressions and build/install the Python wheel before public API tests on Python 3.10 and 3.15 (allow prerelease builds until stable 3.15 is available).

Update Rust rsloop to stable crate 0.1.56, wreq to stable 0.16.1, and PyO3 to 0.29.3; refresh Cargo.lock and uv.lock (Python rsloop 0.1.59). Declare Python >=3.10 and Rust >=1.98. Adapt proxy parsing, idle-pool disabling, and streaming reads to the current wreq API.

The new wreq proxy matcher silently ignores unsupported schemes: invalid://proxy can send a request directly and report success. Validate supported HTTP/HTTPS/SOCKS schemes before sending, retain bare host:port inputs, and return failed outcomes for unsupported schemes. Add parser tests and a local Python HTTP target test that verifies invalid proxies never reach the target directly. Preserve full-body return and body-read error behavior.

Add a Keep a Changelog / Semantic Versioning changelog with Unreleased changes; retain package version 0.1.0. Document build prerequisites and checks. Fix Clippy findings; allow only the owned PyO3 iterator receiver lint.

Validation: pedantic Clippy passed; 5 Rust tests passed; rebuilt CPython 3.12 wheel and 3 Python API tests passed; formatting and diff checks passed. The deterministic proxy-bypass regression reproduces the failure against the previous wheel and passes with this fix. Earlier wheel/API checks also passed on CPython 3.14. GitHub CI is rerun for the updated head.