feat(agent): integrate skill discovery into Dream consolidation

Instead of a separate skill discovery system, extend Dream's two-phase
pipeline to also detect reusable behavioral patterns from conversation
history and generate SKILL.md files.

Phase 1 gains a [SKILL] output type for pattern detection.
Phase 2 gains write_file (scoped to skills/) and read access to builtin
skills, enabling it to check for duplicates and follow skill-creator's
format conventions before creating new skills.

Inspired by PR #3039 by @wanghesong2019.

Co-authored-by: wanghesong2019 <wanghesong2019@users.noreply.github.com>

nanobot/agent/memory.py

@@ -582,14 +582,53 @@ class Dream:
 
     def _build_tools(self) -> ToolRegistry:
         """Build a minimal tool registry for the Dream agent."""
-        from nanobot.agent.tools.filesystem import EditFileTool, ReadFileTool
+        from nanobot.agent.skills import BUILTIN_SKILLS_DIR
+        from nanobot.agent.tools.filesystem import EditFileTool, ReadFileTool, WriteFileTool
 
         tools = ToolRegistry()
         workspace = self.store.workspace
-        tools.register(ReadFileTool(workspace=workspace, allowed_dir=workspace))
+        # Allow reading builtin skills for reference during skill creation
+        extra_read = [BUILTIN_SKILLS_DIR] if BUILTIN_SKILLS_DIR.exists() else None
+        tools.register(ReadFileTool(
+            workspace=workspace,
+            allowed_dir=workspace,
+            extra_allowed_dirs=extra_read,
+        ))
         tools.register(EditFileTool(workspace=workspace, allowed_dir=workspace))
+        # write_file scoped to skills/ directory for skill creation
+        skills_dir = workspace / "skills"
+        skills_dir.mkdir(parents=True, exist_ok=True)
+        tools.register(WriteFileTool(workspace=skills_dir, allowed_dir=skills_dir))
         return tools
 
+    # -- skill listing --------------------------------------------------------
+
+    def _list_existing_skills(self) -> list[str]:
+        """List existing skills as 'name — description' for dedup context."""
+        import re as _re
+
+        from nanobot.agent.skills import BUILTIN_SKILLS_DIR
+
+        _DESC_RE = _re.compile(r"^description:\s*(.+)$", _re.MULTILINE | _re.IGNORECASE)
+        entries: dict[str, str] = {}
+        for base in (self.store.workspace / "skills", BUILTIN_SKILLS_DIR):
+            if not base.exists():
+                continue
+            for d in base.iterdir():
+                if not d.is_dir():
+                    continue
+                skill_md = d / "SKILL.md"
+                if not skill_md.exists():
+                    continue
+                # Prefer workspace skills over builtin (same name)
+                if d.name in entries and base == BUILTIN_SKILLS_DIR:
+                    continue
+                content = skill_md.read_text(encoding="utf-8")[:500]
+                m = _DESC_RE.search(content)
+                desc = m.group(1).strip() if m else "(no description)"
+                entries[d.name] = desc
+        return [f"{name} — {desc}" for name, desc in sorted(entries.items())]
+
     # -- main entry ----------------------------------------------------------
 
     async def run(self) -> bool:
@@ -615,6 +654,7 @@ class Dream:
         current_memory = self.store.read_memory() or "(empty)"
         current_soul = self.store.read_soul() or "(empty)"
         current_user = self.store.read_user() or "(empty)"
+
         file_context = (
             f"## Current Date\n{current_date}\n\n"
             f"## Current MEMORY.md ({len(current_memory)} chars)\n{current_memory}\n\n"
@@ -622,7 +662,7 @@ class Dream:
             f"## Current USER.md ({len(current_user)} chars)\n{current_user}"
         )
 
-        # Phase 1: Analyze
+        # Phase 1: Analyze (no skills list — dedup is Phase 2's job)
         phase1_prompt = (
             f"## Conversation History\n{history_text}\n\n{file_context}"
         )
@@ -647,7 +687,14 @@ class Dream:
             return False
 
         # Phase 2: Delegate to AgentRunner with read_file / edit_file
-        phase2_prompt = f"## Analysis Result\n{analysis}\n\n{file_context}"
+        existing_skills = self._list_existing_skills()
+        skills_section = ""
+        if existing_skills:
+            skills_section = (
+                "\n\n## Existing Skills\n"
+                + "\n".join(f"- {s}" for s in existing_skills)
+            )
+        phase2_prompt = f"## Analysis Result\n{analysis}\n\n{file_context}{skills_section}"
 
         tools = self._tools
         messages: list[dict[str, Any]] = [

nanobot/templates/agent/dream_phase1.md

@@ -3,6 +3,7 @@ Compare conversation history against current memory files. Also scan memory file
 Output one line per finding:
 [FILE] atomic fact (not already in memory)
 [FILE-REMOVE] reason for removal
+[SKILL] kebab-case-name: one-line description of the reusable pattern
 
 Files: USER (identity, preferences), SOUL (bot behavior, tone), MEMORY (knowledge, project context)
 
@@ -18,6 +19,12 @@ Staleness — flag for [FILE-REMOVE]:
 - Detailed incident info after 14 days — reduce to one-line summary
 - Superseded: approaches replaced by newer solutions, deprecated dependencies
 
+Skill discovery — flag [SKILL] when ALL of these are true:
+- A specific, repeatable workflow appeared 2+ times in the conversation history
+- It involves clear steps (not vague preferences like "likes concise answers")
+- It is substantial enough to warrant its own instruction set (not trivial like "read a file")
+- Do not worry about duplicates — the next phase will check against existing skills
+
 Do not add: current weather, transient status, temporary errors, conversational filler.
 
 [SKIP] if nothing needs updating.

nanobot/templates/agent/dream_phase2.md

@@ -1,11 +1,13 @@
 Update memory files based on the analysis below.
 - [FILE] entries: add the described content to the appropriate file
 - [FILE-REMOVE] entries: delete the corresponding content from memory files
+- [SKILL] entries: create a new skill under skills/<name>/SKILL.md using write_file
 
 ## File paths (relative to workspace root)
 - SOUL.md
 - USER.md
 - memory/MEMORY.md
+- skills/<name>/SKILL.md (for [SKILL] entries only)
 
 Do NOT guess paths.
 
@@ -17,6 +19,17 @@ Do NOT guess paths.
 - Surgical edits only — never rewrite entire files
 - If nothing to update, stop without calling tools
 
+## Skill creation rules (for [SKILL] entries)
+- Use write_file to create skills/<name>/SKILL.md
+- Before writing, read_file skills/skill-creator/SKILL.md for format reference (frontmatter structure, naming conventions, quality standards)
+- **Dedup check**: read existing skills listed below to verify the new skill is not functionally redundant. Skip creation if an existing skill already covers the same workflow.
+- Include YAML frontmatter with name and description fields
+- Keep SKILL.md under 2000 words — concise and actionable
+- Include: when to use, steps, output format, at least one example
+- Do NOT overwrite existing skills — skip if the skill directory already exists
+- Reference specific tools the agent has access to (read_file, write_file, exec, web_search, etc.)
+- Skills are instruction sets, not code — do not include implementation code
+
 ## Quality
 - Every line must carry standalone value
 - Concise bullets under clear headers