fix(qoder): recover incomplete forward destroys

[heimanba]

Summary

• Allow destroy to proceed when a Qoder Forward default Memory Store has neither a tracked Template nor a tracked Identity after an incomplete apply.
• Require --cascade to archive an in-use Forward Environment when Qoder rejects physical deletion.
• Add regression coverage for both paths.

Why

Destroy was blocked by a configured default Memory Store that could not have been created because neither owner was present in local state. After fixing that, Qoder rejected the in-use Forward Environment and directed the caller to archive it.

Type

• Bug fix
• Tests

Surface area

• Provider interface / adapter contract
• State management
• Execution / planning logic
• Tests / fixtures

Checklist

• bun run verify:full passes
• No new runtime dependencies added without justification

Behavior / risk

When neither a Template nor an Identity is tracked, destroy no longer invents a default Memory Store cleanup dependency. A partially tracked owner set remains protected. For Qoder Forward, an environment that cannot be deleted due to retained session references is archived only after explicit --cascade.

Validation

• bun scripts/verify.ts push (pre-push hook)
• bun test packages/sdk/tests/unit/destroy-runtime.test.ts packages/sdk/tests/unit/qoder-forward-template.test.ts
• bun run --cwd packages/sdk typecheck