Fix C06 C08 C09 live qualification harness

[KeyffMS]

Summary

Replaces the remaining harness-blocked C06, C08, and C09 paths with deterministic live probes. C13 and baseline 2.2 are intentionally unchanged.

C06 — real PreToolUse + mandatory postcondition

• installs the real PlanAnvil release and real plan-anvil-guard.py PreToolUse hook;
• wraps the real hook only to record sanitized event/tool-name structure;
• requires a direct apply_patch tool call to produce a real PreToolUse observation;
• separately performs a controlled mutation outside the Codex hook lifecycle and requires Git postcondition detection without assuming hook interception.

C08 — deterministic PreCompact stop and repair

• creates a real active PlanAnvil generation run with no valid checkpoint;
• uses model_auto_compact_token_limit = 200 and model_auto_compact_token_limit_scope = "body_after_prefix", redundantly applied by CLI;
• forces genuine automatic compaction through a large tool-result payload;
• requires the real plan-anvil-compaction.py PreCompact hook to return continue=false with checkpoint/recovery semantics and no PostCompact;
• creates a real generation checkpoint and repeats the probe, requiring PreCompact + PostCompact with no stop to prove the blocker is repairable rather than permanent.

C09 — repeated genuine compaction and recovery

• starts with a schema-valid real generation checkpoint;
• uses a 1000-token body_after_prefix automatic-compaction budget plus large deterministic payload segments;
• records real PreCompact/PostCompact/PreToolUse events while delegating to the real product hooks;
• requires at least two completed compaction cycles;
• validates the real checkpoint against canonical state/Git before and after compaction;
• requires a real tool call after the second PostCompact to prove the session did not enter a permanent stop loop.

Safety / scope

• no sandbox or approval bypass;
• no danger-full-access, privileged container, or extra capabilities;
• model-tool network remains disabled;
• self-hosted qualification remains workflow_dispatch-only from main;
• this PR itself uses only the ordinary hosted CI matrix;
• C13 remains tracked separately in Analyze C13 SubagentStart assumptions under codex exec --ephemeral #17.