Summary

• Adds a "sync before patch" rule to the plan step of the fix-obi agent workflow
• Prevents the agent from silently patching a failing test assertion when the correct fix is to remove the test block entirely (because OBI removed it upstream)

Context

When an OBI commit removes a feature/option, its test block is also removed upstream. Previously, the plan agent could see a failing Beyla assertion and produce a plan to adjust it (e.g. assert.False(...)) — technically making it green, but diverging from upstream intent.

The new rule instructs the agent to first locate the same test in .obi-src/, compare the failing block against the OBI version, and:

• Remove the block if OBI removed it (applying the normal OBI→Beyla translation rules)
• Adjust the assertion only if the block still exists in OBI but the expected value changed

Example that motivated this change

TestWillUseTC in Beyla's config_test.go — OBI removed the "ip" sub-case in
open-telemetry/opentelemetry-ebpf-instrumentation@56db2407, but the agent patched
the assertion instead of removing the block.