the model is the agent, the code is the harness

Comprehensive rewrite establishing the harness engineering narrative
across the entire repository.

README (EN/ZH/JA): added "The Model IS the Agent" manifesto with
historical proof (DQN, OpenAI Five, AlphaStar, Tencent Jueyu),
"What an Agent Is NOT" critique, harness engineer role definition,
"Why Claude Code" as masterclass in harness design, and universe
vision. Consistent framing: model = driver, harness = vehicle.

docs (36 files, 3 languages): injected one-line "Harness layer"
callout after the motto in every session document (s01-s12).

agents (13 Python files): added harness framing comment before
each module docstring.

skills/agent-philosophy.md: full rewrite aligned with harness
narrative.

docs/en/s01-the-agent-loop.md

@@ -3,6 +3,8 @@
 `[ s01 ] s02 > s03 > s04 > s05 > s06 | s07 > s08 > s09 > s10 > s11 > s12`
 
 > *"One loop & Bash is all you need"* -- one tool + one loop = an agent.
+>
+> **Harness layer**: The loop -- the model's first connection to the real world.
 
 ## Problem
 

docs/en/s02-tool-use.md

@@ -3,6 +3,8 @@
 `s01 > [ s02 ] s03 > s04 > s05 > s06 | s07 > s08 > s09 > s10 > s11 > s12`
 
 > *"Adding a tool means adding one handler"* -- the loop stays the same; new tools register into the dispatch map.
+>
+> **Harness layer**: Tool dispatch -- expanding what the model can reach.
 
 ## Problem
 

docs/en/s03-todo-write.md

@@ -3,6 +3,8 @@
 `s01 > s02 > [ s03 ] s04 > s05 > s06 | s07 > s08 > s09 > s10 > s11 > s12`
 
 > *"An agent without a plan drifts"* -- list the steps first, then execute.
+>
+> **Harness layer**: Planning -- keeping the model on course without scripting the route.
 
 ## Problem
 

docs/en/s04-subagent.md

@@ -3,6 +3,8 @@
 `s01 > s02 > s03 > [ s04 ] s05 > s06 | s07 > s08 > s09 > s10 > s11 > s12`
 
 > *"Break big tasks down; each subtask gets a clean context"* -- subagents use independent messages[], keeping the main conversation clean.
+>
+> **Harness layer**: Context isolation -- protecting the model's clarity of thought.
 
 ## Problem
 

docs/en/s05-skill-loading.md

@@ -3,6 +3,8 @@
 `s01 > s02 > s03 > s04 > [ s05 ] s06 | s07 > s08 > s09 > s10 > s11 > s12`
 
 > *"Load knowledge when you need it, not upfront"* -- inject via tool_result, not the system prompt.
+>
+> **Harness layer**: On-demand knowledge -- domain expertise, loaded when the model asks.
 
 ## Problem
 

docs/en/s06-context-compact.md

@@ -3,6 +3,8 @@
 `s01 > s02 > s03 > s04 > s05 > [ s06 ] | s07 > s08 > s09 > s10 > s11 > s12`
 
 > *"Context will fill up; you need a way to make room"* -- three-layer compression strategy for infinite sessions.
+>
+> **Harness layer**: Compression -- clean memory for infinite sessions.
 
 ## Problem
 

docs/en/s07-task-system.md

@@ -3,6 +3,8 @@
 `s01 > s02 > s03 > s04 > s05 > s06 | [ s07 ] s08 > s09 > s10 > s11 > s12`
 
 > *"Break big goals into small tasks, order them, persist to disk"* -- a file-based task graph with dependencies, laying the foundation for multi-agent collaboration.
+>
+> **Harness layer**: Persistent tasks -- goals that outlive any single conversation.
 
 ## Problem
 

docs/en/s08-background-tasks.md

@@ -3,6 +3,8 @@
 `s01 > s02 > s03 > s04 > s05 > s06 | s07 > [ s08 ] s09 > s10 > s11 > s12`
 
 > *"Run slow operations in the background; the agent keeps thinking"* -- daemon threads run commands, inject notifications on completion.
+>
+> **Harness layer**: Background execution -- the model thinks while the harness waits.
 
 ## Problem
 

docs/en/s09-agent-teams.md

@@ -3,6 +3,8 @@
 `s01 > s02 > s03 > s04 > s05 > s06 | s07 > s08 > [ s09 ] s10 > s11 > s12`
 
 > *"When the task is too big for one, delegate to teammates"* -- persistent teammates + async mailboxes.
+>
+> **Harness layer**: Team mailboxes -- multiple models, coordinated through files.
 
 ## Problem
 

docs/en/s10-team-protocols.md

@@ -3,6 +3,8 @@
 `s01 > s02 > s03 > s04 > s05 > s06 | s07 > s08 > s09 > [ s10 ] s11 > s12`
 
 > *"Teammates need shared communication rules"* -- one request-response pattern drives all negotiation.
+>
+> **Harness layer**: Protocols -- structured handshakes between models.
 
 ## Problem
 

docs/en/s11-autonomous-agents.md

@@ -3,6 +3,8 @@
 `s01 > s02 > s03 > s04 > s05 > s06 | s07 > s08 > s09 > s10 > [ s11 ] s12`
 
 > *"Teammates scan the board and claim tasks themselves"* -- no need for the lead to assign each one.
+>
+> **Harness layer**: Autonomy -- models that find work without being told.
 
 ## Problem
 

docs/en/s12-worktree-task-isolation.md

@@ -3,6 +3,8 @@
 `s01 > s02 > s03 > s04 > s05 > s06 | s07 > s08 > s09 > s10 > s11 > [ s12 ]`
 
 > *"Each works in its own directory, no interference"* -- tasks manage goals, worktrees manage directories, bound by ID.
+>
+> **Harness layer**: Directory isolation -- parallel execution lanes that never collide.
 
 ## Problem