feat: Add ORCH — OrchestratorAgent Unit Tests (Bug_202, Bug_203)

- 62 tests across 11 groups: ORCH-INIT, ORCH-CFG, ORCH-PROMPT, ORCH-TOOLS,
  ORCH-DELIM, ORCH-CTX, ORCH-DEL, ORCH-EVENT, ORCH-CTF, ORCH-EDGE, ORCH-QA
- 61 passing / 2 failing (ORCH-QA-001, ORCH-QA-002) — real bugs Bug_202, Bug_203
- CTF vulnerability tests confirm 3 known vulnerabilities are present:
  context injection, whitespace summary bypass, unconditional payment_confirmation

Author: steadhac