feat: openclaw-style secrets (env.vars + \) and per-task model routing

- Replace python-dotenv with config.json env.vars block + \ substitution
- Add models section for per-task model routing (heartbeat, subagent, default)
- Heartbeat/subagent tasks can use different models/providers than main chat
- Remove python-dotenv from dependencies
- Update all docs to reflect new config approach
- Reorganize docs into project/ and research/ subdirectories

docs/project/additions.txt

@@ -0,0 +1,21 @@
+# completed
+config instead of env
+openclaw-style secrets in config.json (env.vars + ${VAR} substitution, removed python-dotenv dependency)
+per-task model routing (models.heartbeat, models.subagent, models.default — different models for different task types)
+edit its own files and config as well as add skills
+start command for all instead of flags use config
+customize opencode/claudecode setup like llms and providers during setup, agent creation/modify for claudecode and opencode
+install script starts server and adds the aetheel command
+llm usage stats
+logo
+discord advanced features (reply threading, history context, ack reactions, typing indicators, reaction handling, slash commands, interactive components, exec approvals)
+opencode advanced features (agent selection, attach mode, file attachments, session fork/title, models listing, stats, agents listing)
+
+
+# Not complete
+agent to agent and agent orchestration
+better UI
+human in the loop
+security
+browse plugins and skills from claude marketplace or opencode 
+self modification docs