chore(scale): prove full and incremental analysis convergence

[parthrohit22]

Parent: #210

Goal

Establish the convergence gate between full and incremental analysis before evolution work begins.

Scope

• Define representative repository classes and bounded resource budgets.
• Run full and incremental analysis over the same sealed revisions.
• Compare canonical graph hashes and decision-relevant facts.
• Record explainable differences and failure recovery behavior.
• Keep unsupported frameworks and rename/move identity work explicitly out of scope.

Acceptance criteria

• Full and incremental runs converge for the selected repository classes.
• Budget exhaustion is deterministic and observable.
• Differences are classified rather than hidden.
• The test fixture contains no partner/private repository data.
• The resulting report can serve as the GATE B decision record.

[parthrohit22]

PARTHA is self-hosted only. Reopen together with #326 if re-analysis speed becomes a real complaint.