feat: add skills, memory, delegation and self-learning (Phase 3)

Add three Hermes-inspired capabilities to Shira:

- Skills system: firm-wide workflow templates (list/view/manage tools),
  4 pre-seeded skills (case summary, hearing prep, direct access report,
  deadline tracker), auto-learning via post-conversation meta-prompt
- Cross-conversation memory: per-lawyer profiles and per-case memory
  stored as bounded markdown files, injected into system prompts
- Sub-agent delegation: spawn up to 3 child AgentRunner instances for
  parallel document analysis and complex multi-step tasks

New files: skills.py, memory.py, delegate.py, learner.py, 4 SKILL.md
Updated: agent_runner (6 new tools, depth/blocked_tools support),
prompt_builder (skills/memory injection), route (memory loading,
background learning), main.py (data dirs), Dockerfile (pyyaml, skills)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

api/services/skills.py

@@ -0,0 +1,139 @@
+"""Skills engine — list, view, manage, and register skill tools."""
+
+from __future__ import annotations
+
+import logging
+import os
+from pathlib import Path
+
+import yaml
+
+logger = logging.getLogger("shira.skills")
+
+SKILLS_DIR = os.environ.get("SHIRA_DATA_DIR", "/opt/data") + "/skills"
+
+
+def _parse_frontmatter(text: str) -> tuple[dict, str]:
+    """Parse YAML frontmatter from a SKILL.md file. Returns (meta, body)."""
+    if not text.startswith("---"):
+        return {}, text
+    end = text.find("---", 3)
+    if end == -1:
+        return {}, text
+    try:
+        meta = yaml.safe_load(text[3:end]) or {}
+    except yaml.YAMLError:
+        meta = {}
+    body = text[end + 3:].lstrip("\n")
+    return meta, body
+
+
+def list_skills() -> list[dict]:
+    """Scan the skills directory and return metadata for each skill."""
+    skills_path = Path(SKILLS_DIR)
+    if not skills_path.exists():
+        return []
+
+    result = []
+    for entry in sorted(skills_path.iterdir()):
+        skill_file = entry / "SKILL.md" if entry.is_dir() else None
+        if not skill_file or not skill_file.exists():
+            continue
+        try:
+            meta, _ = _parse_frontmatter(skill_file.read_text(encoding="utf-8"))
+            result.append({
+                "name": meta.get("name", entry.name),
+                "description": meta.get("description", ""),
+                "version": meta.get("version", "1.0.0"),
+            })
+        except Exception as e:
+            logger.warning("Failed to parse skill %s: %s", entry.name, e)
+    return result
+
+
+def view_skill(skill_name: str) -> str | None:
+    """Load the full SKILL.md content for a given skill name."""
+    skill_file = Path(SKILLS_DIR) / skill_name / "SKILL.md"
+    if not skill_file.exists():
+        return None
+    return skill_file.read_text(encoding="utf-8")
+
+
+def save_skill(skill_name: str, content: str) -> None:
+    """Create or overwrite a skill file."""
+    skill_dir = Path(SKILLS_DIR) / skill_name
+    skill_dir.mkdir(parents=True, exist_ok=True)
+    (skill_dir / "SKILL.md").write_text(content, encoding="utf-8")
+    logger.info("Saved skill: %s", skill_name)
+
+
+def register_skill_tools(tools: dict) -> None:
+    """Register skill-related tools into the tools dict."""
+
+    async def skills_list() -> str:
+        import json
+        skills = list_skills()
+        if not skills:
+            return "אין skills זמינים כרגע."
+        lines = ["Skills זמינים:"]
+        for s in skills:
+            lines.append(f'- **{s["name"]}**: {s["description"]}')
+        return "\n".join(lines)
+
+    async def skill_view(skill_name: str) -> str:
+        content = view_skill(skill_name)
+        if content is None:
+            return f'❌ Skill "{skill_name}" לא נמצא.'
+        return content
+
+    async def skill_manage(action: str, skill_name: str, content: str = "") -> str:
+        if action == "create":
+            if not content:
+                return "❌ צריך לספק תוכן ל-skill חדש."
+            existing = view_skill(skill_name)
+            if existing:
+                return f'❌ Skill "{skill_name}" כבר קיים. השתמש ב-action "update" כדי לעדכן.'
+            save_skill(skill_name, content)
+            return f'✅ Skill "{skill_name}" נוצר בהצלחה.'
+        elif action == "update":
+            existing = view_skill(skill_name)
+            if not existing:
+                return f'❌ Skill "{skill_name}" לא נמצא. השתמש ב-action "create" כדי ליצור.'
+            if not content:
+                return "❌ צריך לספק תוכן מעודכן."
+            save_skill(skill_name, content)
+            return f'✅ Skill "{skill_name}" עודכן בהצלחה.'
+        else:
+            return f'❌ פעולה לא מוכרת: {action}. השתמש ב-"create" או "update".'
+
+    tools["skills_list"] = {
+        "description": "List all available skills (learned workflows and templates). Returns skill names and descriptions.",
+        "parameters": {"type": "object", "properties": {}, "required": []},
+        "handler": skills_list,
+    }
+
+    tools["skill_view"] = {
+        "description": "View the full content of a specific skill. Use after skills_list to load a relevant workflow before a complex task.",
+        "parameters": {
+            "type": "object",
+            "properties": {
+                "skill_name": {"type": "string", "description": "The skill name (from skills_list)"},
+            },
+            "required": ["skill_name"],
+        },
+        "handler": skill_view,
+    }
+
+    tools["skill_manage"] = {
+        "description": "Create or update a skill. Use when you discover a reusable workflow pattern during a conversation.",
+        "parameters": {
+            "type": "object",
+            "properties": {
+                "action": {"type": "string", "enum": ["create", "update"], "description": "Create new or update existing"},
+                "skill_name": {"type": "string", "description": "Skill name (lowercase-dashes)"},
+                "content": {"type": "string", "description": "Full skill content in markdown with YAML frontmatter"},
+            },
+            "required": ["action", "skill_name", "content"],
+        },
+        "handler": skill_manage,
+    }