Consultant escalation policy + milestone delivery checks

Manager policy, active only when a company employs a consultant:
- a task that blows its wall-clock budget or blocks on machine failure
  (crashed worker, capability gap — anything except needs_input) is
  reassigned to the consultant with the failure context appended
- every objective rollup spawns a consultant review task: verify each
  deliverable against acceptance criteria, write milestone-check.md,
  verdict per deliverable, fix nothing

Also: employee_role_check widened to include consultant (db + live);
consultant sprite shirt color in the office.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

db/schema.sql

@@ -19,7 +19,7 @@ CREATE TABLE employee (
     name            text NOT NULL,
     title           text NOT NULL,
     role            text NOT NULL DEFAULT 'engineer'
-                    CHECK (role IN ('manager','engineer','qa')),
+                    CHECK (role IN ('manager','engineer','qa','consultant')),
     department      text NOT NULL DEFAULT '',
     manager_id      uuid REFERENCES employee(id),
     hermes_profile  text,                       -- Hermes profile name (ADR-001)