SEP-019: Missing tests for compaction recovery path

[samudzi]

Summary

ARCHITECTURE.md Section 8 specifies a decision tree the model must follow after compaction. The check_clear_approval_command.sh injection is the mechanism. But test_hooks.sh doesn't test:

1. What the injected WORKFLOW STATE looks like immediately after EnterPlanMode with a rich previous plan
2. Whether the planning injection correctly enriches with previous objective from the plans table when breadcrumb keys are empty
3. The no-token fallback after compaction

Motivation

Compaction recovery is a critical path — if the model loses context and the injection doesn't correctly restore state, the entire workflow breaks silently. This path is untested.

Proposed Change

Add test cases covering:

• EnterPlanMode injection with existing plan state
• Planning injection enrichment from plans table when breadcrumb keys are empty
• No-token fallback behavior after compaction

Acceptance Criteria

• Tests verify correct WORKFLOW STATE injection after EnterPlanMode
• Tests verify planning injection enrichment from plans table
• Tests verify no-token fallback produces usable state