directive: make the HexIntFactor pair publication-ready

[kim-em]

libraries: HexIntFactor, HexIntFactorMathlib
depends-on: #9638
depends-on: #9767

Goal

Make the HexIntFactor core and bridge publication-ready through Phase 7. This directive is the final join between local IntFactor readiness and the upstream primality Phase-4 prerequisite.

Current work graph

• feat: complete HexIntFactor Phase-2/3 review and conformance package #9627 owns IntFactor review tokens, route conformance, oracle coverage, and Phase-2/3 evidence.
• perf: complete HexIntFactor Phase-4 evidence with decomposed factorization costs #9634 independently owns the complete Phase-4 benchmark/report package.
• chore: finish HexIntFactor polish, docs, and local publication readiness #9638 joins those local packages and completes proof/API polish, READMEs, the manual chapter, and local Phase-5–7 readiness.
• chore(hex-primality): certify the pair as a Phase-4 prerequisite #9767 independently certifies the primality pair through Phase 4.
• This directive records the final dependency-coupled counters and closes only after chore: finish HexIntFactor polish, docs, and local publication readiness #9638 and chore(hex-primality): certify the pair as a Phase-4 prerequisite #9767 are both complete.

Closed #9628, #9635, #9636, and #9637 are absorbed into the surviving local packages and are historical references only.

Final acceptance

• Verify the locally ready IntFactor commit against the accepted primality Phase-4 commit.
• Run the complete build, conformance/oracle, benchmark, report-reproduction, phase-artifact, DAG, linter, README/manual, and full CI suite.
• Record only counters supported by both local artifacts and upstream dependency state.
• Close the directive only when both libraries genuinely satisfy Phase 7.

Out of scope

• Adding either repository to released.yml.
• Syncing or hand-editing released mirrors, creating tags, or updating aggregate pins.

[kim-em]

Claimed for decomposition and execution. Session: manual-codex-session.