Initial project structure

Scaffold all modules, route stubs, data models, and config.
No logic implemented yet — all core methods raise NotImplementedError.
Establishes the full directory layout matching the architecture in CLAUDE.md.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

fellowship/api/events.py

@@ -0,0 +1,83 @@
+"""
+All WebSocket/SSE event types sent from Fellowship to connected members.
+Every event is a Pydantic model serialized to JSON.
+"""
+
+from typing import Any, Literal
+from pydantic import BaseModel
+
+
+class HistoryEvent(BaseModel):
+    type: Literal["history"] = "history"
+    messages: list[dict[str, Any]]
+
+
+class TurnStartEvent(BaseModel):
+    type: Literal["turn_start"] = "turn_start"
+    bot: str
+    turn: int
+
+
+class BotMessageEvent(BaseModel):
+    type: Literal["bot_message"] = "bot_message"
+    bot: str
+    content: str
+    turn: int
+
+
+class TokenEvent(BaseModel):
+    """Only emitted when stream_tokens is enabled."""
+    type: Literal["token"] = "token"
+    bot: str
+    token: str
+    turn: int
+
+
+class TurnEndEvent(BaseModel):
+    type: Literal["turn_end"] = "turn_end"
+    bot: str
+    turn: int
+    tokens: int
+
+
+class TalkerMessageEvent(BaseModel):
+    type: Literal["talker_message"] = "talker_message"
+    talker_id: str
+    talker_name: str
+    content: str
+    turn: int
+
+
+class MemberJoinedEvent(BaseModel):
+    type: Literal["member_joined"] = "member_joined"
+    role: Literal["talker", "observer"]
+
+
+class MemberLeftEvent(BaseModel):
+    type: Literal["member_left"] = "member_left"
+    role: Literal["talker", "observer"]
+
+
+class SessionPausedEvent(BaseModel):
+    type: Literal["session_paused"] = "session_paused"
+
+
+class SessionResumedEvent(BaseModel):
+    type: Literal["session_resumed"] = "session_resumed"
+
+
+class SessionEndEvent(BaseModel):
+    type: Literal["session_end"] = "session_end"
+    reason: Literal["max_turns", "max_time", "max_context", "orchestrator", "client_request"]
+
+
+class ErrorEvent(BaseModel):
+    type: Literal["error"] = "error"
+    message: str
+
+
+class DebugEvent(BaseModel):
+    """Only emitted when debug mode is active."""
+    type: Literal["debug"] = "debug"
+    category: str
+    data: dict[str, Any]