release: align plugins with AKM 0.9.2

[itlackey]

Summary

• raise the supported AKM floor to 0.9.2
• align Claude and OpenCode runtimes with the 0.9.2 ref, search, proposal, workflow, and extraction contracts
• refresh fixtures, eval harnesses, documentation, and release metadata
• lock OpenCode to the published akm-cli 0.9.2 package

Validation

• 285 plugin tests pass
• Claude and OpenCode typechecks pass
• frozen OpenCode dependency install passes
• Tier-2 evaluation diff reports no regressions
• Tier-3 stub scenarios pass 8/8

[github-actions]

Eval diff

• Baseline SHA: 83de80205da91f6789ffeb9b063f8b89ed91f730
• Candidate SHA: fb15198386f3dd2c723740d71f165fb7531ec818

Metric deltas

Metric	Key	Baseline	Candidate	Δ	Δ%	Status
curation	mean_expected_coverage	0.9125	0.9125	0	0.00%	• unchanged
curation	mean_reciprocal_rank	0.9208	0.9208	0	0.00%	• unchanged
curation	zero_hit_rate	0.0500	0.0500	0	0.00%	• unchanged
context_budget	claude_violations	0	0	0	0.00%	• unchanged
context_budget	opencode_violations	0	0	0	0.00%	• unchanged
context_budget	claude_drop_rate	0	0	0	0.00%	• unchanged
context_budget	opencode_drop_rate	0	0	0	0.00%	• unchanged
feedback	claude_precision	1	1	0	0.00%	• unchanged
feedback	claude_recall	1	1	0	0.00%	• unchanged
feedback	claude_polarity_flips	0	0	0	0.00%	• unchanged
feedback	opencode_precision	1	1	0	0.00%	• unchanged
feedback	opencode_recall	1	1	0	0.00%	• unchanged
feedback	opencode_polarity_flips	0	0	0	0.00%	• unchanged

Plugin surface

No surface changes.

No regressions.