feat(F): F-WORK agent_workstream + F-EMAIL/CONTACT/FOLLOW/REPORT prebuilt agents

- F-WORK: app/ai/agent_workstream.py (201 lines) — post_agent_message, post_agent_step, post_agent_result, post_approval_request
- F-EMAIL: prebuilt/email_triage_agent.py — E-Mail-Triage-Agent with 3 tools, max 10 steps, $0.50 budget
- F-CONTACT: prebuilt/contact_enrichment_agent.py — Contact-Enrichment-Agent with 3 tools, max 8 steps, $0.30 budget
- F-FOLLOW: prebuilt/follow_up_agent.py — Follow-up-Agent with 3 tools, max 8 steps, $0.30 budget
- F-REPORT: prebuilt/report_agent.py — Report-Agent with 2 tools, max 12 steps, $0.50 budget
- All compile checks pass

app/plugins/builtins/automation/prebuilt/report_agent.py

@@ -0,0 +1,50 @@
+"""Pre-built Report-Agent.
+
+Generates reports from CRM data using search and API tools.
+"""
+from __future__ import annotations
+import uuid
+from app.plugins.builtins.automation.models import AgentDefinition
+
+REPORT_SYSTEM_PROMPT = """You are a Report Agent for a CRM system.
+
+Your task is to generate reports from CRM data.
+
+You can:
+1. Search for contacts, companies, and activities using hybrid search
+2. Call CRM API for structured data (contacts, companies, tasks, calendar)
+3. Aggregate and summarize data into reports
+4. Format reports as markdown with tables and sections
+
+Report types you can generate:
+- Contact activity summary (interactions, emails, tasks per contact)
+- Sales pipeline overview (contacts by status, recent changes)
+- Task completion report (open vs done, overdue, by assignee)
+- Communication summary (email volume, response times)
+- Custom reports based on user request
+
+Use the available tools to gather data, then format a clear, structured report.
+Include relevant metrics, dates, and entity references.
+Be concise but comprehensive. Use markdown formatting.
+"""
+
+def create_report_agent(
+    tenant_id: uuid.UUID, user_id: uuid.UUID
+) -> AgentDefinition:
+    return AgentDefinition(
+        tenant_id=tenant_id,
+        name="Report-Agent",
+        description="Generiert Berichte aus CRM-Daten",
+        system_prompt=REPORT_SYSTEM_PROMPT,
+        llm_model="openai/gpt-4o-mini",
+        tool_ids=["call_crm_api", "hybrid_search"],
+        max_steps=12,
+        max_duration_seconds=180,
+        budget_limit_usd=0.50,
+        mode="reactive",
+        is_active=True,
+        temperature=0.3,
+        max_tokens=3000,
+        trace_mode="standard",
+        created_by=user_id,
+    )