fix(plugins): recover missing Rust implementation for url_reputation plugin (#38)

* fix(plugins): recover missing Rust implementation for url_reputation plugin

The url_reputation plugin was missing its complete Rust implementation
after migration from mcp-context-forge. This commit recovers all missing
Rust source files from git history (commit 8bb308c50).

Recovered files:
- src/engine.rs (707 lines) - Core validation engine
- src/types.rs (79 lines) - Type definitions and PyO3 bindings
- src/filters/ - Heuristic, IANA TLD, and pattern filters
- benches/url_validation.rs - Performance benchmarks
- Enhanced test suite and documentation

The plugin now has complete functionality including:
- URL reputation validation with configurable policies
- Heuristic entropy-based checks
- IANA TLD validation
- Pattern-based allow/block lists
- Domain whitelist/blocklist support
- HTTP/HTTPS scheme enforcement

Updated Cargo.toml with required dependencies:
- idna, url, regex for URL parsing and validation
- phf for efficient TLD lookups
- unicode-script, unicode-security for domain validation
- criterion for benchmarking

Fixed test imports to use cpex_url_reputation module path.
Added _RUST_AVAILABLE flag for Python fallback detection.

Build verification:
- All 24 Rust unit tests pass
- 30 out of 32 Python tests pass (2 pre-existing test issues)
- Plugin compiles and installs successfully

Signed-off-by: Suresh Kumar Moharajan <suresh.kumar.m@ibm.com>

* fix(plugins): remove Python fallback logic from url_reputation plugin

The url_reputation plugin now requires the Rust implementation and will
raise a clear error if the Rust module is not available, rather than
falling back to a limited Python implementation.

Changes:
- Modified URLReputationPlugin.__init__ to raise RuntimeError if Rust
  module is not available
- Removed all Python fallback tests (test_python_* functions)
- Removed Rust error fallback test (test_rust_error_fallback_blocks_url)
- Plugin now enforces Rust-only operation for consistency and performance

Test results:
- 22 tests passed
- 9 tests skipped (Rust-specific features)
- 0 tests failed

This ensures users get the full Rust-powered functionality or a clear
error message to install the plugin properly with 'make install'.

Signed-off-by: Suresh Kumar Moharajan <suresh.kumar.m@ibm.com>

---------

Signed-off-by: Suresh Kumar Moharajan <suresh.kumar.m@ibm.com>
Co-authored-by: Suresh Kumar Moharajan <suresh.kumar.m@ibm.com>
Signed-off-by: lucarlig <luca.carlig@ibm.com>

Author: 2 people

Cargo.lock

@@ -1,6 +1,6 @@
 [package]
 name = "url_reputation"
-version = "0.1.1"
+version = "0.2.0"
 edition.workspace = true
 authors.workspace = true
 license.workspace = true
@@ -16,5 +16,29 @@ name = "stub_gen"
 path = "src/bin/stub_gen.rs"
 
 [dependencies]
-pyo3 = { workspace = true }
+idna = "1.1.0"
+log = "0.4"
+phf = { version = "0.13.1", features = ["macros"] }
+pyo3 = { workspace = true, features = ["abi3-py311"] }
 pyo3-log = { workspace = true }
+regex = "1.12.3"
+unicode-script = "0.5.8"
+unicode-security = "0.1.2"
+url = "2.5.8"
+
+[dev-dependencies]
+criterion = "0.8.2"
+
+[[bench]]
+name = "url_validation"
+harness = false
+
+[profile.release]
+opt-level = 3
+lto = "fat"
+codegen-units = 1
+strip = true
+
+[profile.bench]
+inherits = "release"
+debug = true