Tenant isolation

route = self.router.route(
    path,
    tenant_id=self.tenant_id,  # ← Instance variable (v0.4.x style)
    agent_id=self.agent_id,    # ← Instance variable (v0.4.x style)
    is_admin=self.is_admin,    # ← Instance variable (v0.4.x style)
    check_write=False,
)

# v0.5.0: No longer accept tenant_id/agent_id/user_id in __init__
# These are set to None - operations must pass subject parameter instead
self.tenant_id: str | None = None
self.agent_id: str | None = None
self.user_id: str | None = None

# "New way" (from docstring)
nx = NexusFS(backend)
nx.read("/file.txt", context=OperationContext(user="alice", ...))

# Instance variables are still used!
nx.tenant_id  # → None (never set!)
nx.agent_id   # → None (never set!)
nx.is_admin   # → False (from init param)

# File operations use these None values:
def read(self, path, context=None):
    route = self.router.route(
        path,
        tenant_id=self.tenant_id,  # ← ALWAYS None!
        agent_id=self.agent_id,    # ← ALWAYS None!
        is_admin=self.is_admin     # ← From init, not context!
    )

# v0.4.x (WORKED):
nx = NexusFS(backend, tenant_id="org_acme", user_id="alice")
nx.write("/workspace/org_acme/alice/file.txt", data)
# ✅ self.tenant_id = "org_acme"
# ✅ Router checks: path tenant matches self.tenant_id
# ✅ Tenant isolation enforced

# v0.5.0 (BROKEN):
nx = NexusFS(backend)  # tenant_id=None
ctx = OperationContext(user="alice", ...)
nx.write("/workspace/org_acme/alice/file.txt", data, context=ctx)
# ❌ self.tenant_id = None
# ❌ Router can't enforce tenant isolation!
# ❌ OperationContext not used for routing!

# Add tenant_id to OperationContext
@dataclass
class OperationContext:
    user: str
    groups: list[str]
    tenant_id: str | None = None  # ← ADD THIS
    is_admin: bool = False
    is_system: bool = False

# Use it in routing
def write(self, path, content, context=None):
    ctx = context or self._default_context

    route = self.router.route(
        path,
        tenant_id=ctx.tenant_id,  # ← From context!
        agent_id=None,  # Or extract from user string
        is_admin=ctx.is_admin,
        check_write=True
    )

# AuthResult already has tenant_id!
@dataclass
class AuthResult:
    authenticated: bool
    subject_id: str
    tenant_id: str | None  # ← Already exists!
    is_admin: bool = False

# RPC server should create context WITH tenant_id
def handle_request(jwt_token):
    auth_result = auth.authenticate(jwt_token)

    ctx = OperationContext(
        user=auth_result.subject_id,
        tenant_id=auth_result.tenant_id,  # ← Pass it through!
        groups=[],
        is_admin=auth_result.is_admin
    )

    nx.write(path, data, context=ctx)

# This is what it TRIES to do now but fails because:
# 1. self.tenant_id is always None
# 2. Can't check if path tenant matches user tenant
# 3. No enforcement

# 1. Update OperationContext
@dataclass
class OperationContext:
    user: str
    groups: list[str]
    tenant_id: str | None = None  # ← ADD
    is_admin: bool = False
    is_system: bool = False

# 2. Update all router.route() calls
def write(self, path, content, context=None):
    ctx = context or self._default_context

    route = self.router.route(
        path,
        tenant_id=ctx.tenant_id,  # ← Use context
        agent_id=None,            # ← Or ctx.agent_id if added
        is_admin=ctx.is_admin,    # ← Use context
        check_write=True
    )

# 3. RPC server: create context from JWT
auth_result = await auth.authenticate(token)
ctx = OperationContext(
    user=auth_result.subject_id,
    tenant_id=auth_result.tenant_id,  # ← From JWT!
    groups=[],
    is_admin=auth_result.is_admin
)