Set Segment Budget

The user edits one campaign's daily budget from the dashboard table.

Thin adapter over :func:set_segment_budget_for_org (the same org-scoped service the public API calls). Reconcile semantic (Q3, confirmed): the edited campaign's daily_limit_usd is set DIRECTLY and the project total becomes the SUM of the outreach campaigns' budgets — the OTHER campaigns are NOT touched. It preserves the sum(campaigns) == anchor invariant by construction, so the reconcile safety-net stays a no-op.

Gated on project.autopilot_enabled (agent-owned split → 409); budget belongs to RUNNING campaigns only (paused/pre-launch → 409). Ownership: the segment's project.org_id must match the caller's current org (miss → 404).