Harden authority and evidence boundaries for v0.4.1

[0xmrma]

Summary

• introduce strict authorization v2 with URL/Host/SNI/CONNECT binding, query scope, and granular header mutation policy
• make cross-origin redirect forwarding deny by default and preserve cookie/connection state for one logical observation
• add canonical plan v2 identity and experiment v8 evidence with accurate partial-correlation semantics
• regenerate the versioned 22-case benchmark and remove audience-targeting language from project files

Root cause

v0.4.0 authorized the URL target without independently binding an explicit Host field, forwarded unrecognized caller fields across authorized origins, reset isolated cookie state at redirect-hop boundaries, and derived plan identity from source digests that did not identify the effective request. Its evidence contract also overstated the absence of cross-run correlation.

Validation

• 292 tests: 290 instrumented tests plus 2 benchmark tests
• critical runtime branch coverage: 94.77%; corrected core: 86.11%
• strict mypy: 19 modules; corrected-core mypy: 7 modules
• critical mutation gate: 18/18 killed
• benchmark: 22/22 expected conclusions, 942 authorized attempts
• Ruff, compileall, 11 JSON Schemas, pip-audit, hash-locked dependency resolution
• wheel and sdist build; Twine checks; clean-wheel resource and CLI smoke

Local Docker smoke was not run because the Docker daemon is unavailable. The repository container workflow remains the authoritative container gate.