ci(crv): add stable same-signer physical test pair

[daniele21]

Scope

Adds a RedactGuard-owned pair-packaging workflow for the frozen CRV physical candidate.

• calls the Harness-owned exact-ref physical host builder; RedactGuard does not check out or build Harness source;
• builds the exact RedactGuard release-ci candidate through the existing canonical packaging script;
• restores one dedicated stable test-only PKCS12 identity from GitHub Secrets only inside the signing steps;
• pins the expected public certificate SHA-256 so accidental key drift fails closed;
• zipaligns/signs Harness + RedactGuard with the same certificate and verifies exact signer equality;
• verifies the Harness APK remains ARM64 and both release package IDs are correct;
• uploads only the signed APK pair plus bounded source/SHA/signer manifest and install notes;
• removes signing material before artifact upload;
• runs automatically when integrated into dev (so the artifact does not depend on main being the default branch), while retaining workflow_dispatch for future replay once the workflow reaches the default branch.

Default candidate refs remain the CRV-100 frozen pair: Harness a30f67b21e24adc6efea838e9a9d65cc78446f28, RedactGuard 4679c23a9a22e5242761fe52af97f4eb7432aec7.

Security boundary

The stable test private key is not committed. The workflow expects CRV_TEST_SIGNING_KEYSTORE_B64, CRV_TEST_SIGNING_STORE_PASSWORD, CRV_TEST_SIGNING_KEY_ALIAS, and CRV_TEST_SIGNING_KEY_PASSWORD as repository secrets. Those secrets are scoped only to the steps that reconstruct/verify/sign with the key. The public frozen test certificate fingerprint is D6E16D72FB557B62248F2D48391B5D86F4EB3DAFC920A214F3165169849100F7.

This signer is for physical development/E2E only. It proves the Android same-signature permission boundary on-device but is explicitly not production/upload-key signing evidence.

Dependency

Uses Harness reusable workflow at exact commit f8207c6c8e34f4310fbeb7e01698d58d7579b4a2 from Harness #483.

Validation

CI/signing/release packaging is security- and release-sensitive, so expected profile is FULL. PR validation must not receive signing secrets; the stable-key lane executes only after trusted dev integration/manual dispatch. Physical ARM64 + real GGUF behavior remains REAL_ENVIRONMENT; the generated pair only prepares its exact install inputs.

[daniele21]

/preflight full