Rename the import package app to fluksio

A wheel whose top-level module is `app` collides with anything else in a
user's venv, so the package that is about to be published takes the name
it is published under. Only the Python package moves; the repo, the
Docker WORKDIR and the compose project keep theirs.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

backend/fluksio/api/routes/messages.py

@@ -0,0 +1,114 @@
+"""Messages: what a dashboard binds to, across every flow.
+
+The flow API is scoped to one flow, which is the wrong shape here — a wall
+panel shows the heating alongside the solar. These endpoints are the whole
+namespace at once: what exists, what it last was, and a way to put a value
+into it without owning a node.
+"""
+
+from typing import Any
+
+from fastapi import APIRouter, Depends, HTTPException
+from fastapi.concurrency import run_in_threadpool
+from pydantic import BaseModel
+
+from fluksio.api.deps import FlowControllerDep, get_current_user
+from fluksio.flow.messages import flow_of
+from fluksio.flow.pipeline import ValueSource
+from fluksio.flow.state import as_number
+
+router = APIRouter(
+    prefix="/messages", tags=["messages"], dependencies=[Depends(get_current_user)]
+)
+
+
+class MessageInfo(BaseModel):
+    """One message, as something to bind a widget to."""
+
+    name: str
+    flow: str
+    dtype: str
+    #: Nodes publishing it. Empty means the flow declares it as an input.
+    providers: list[str] = []
+    #: Whether a dashboard may publish to it — that is, whether it is declared.
+    writable: bool = True
+    numeric: bool = False
+    value: Any = None
+    ts: float | None = None
+
+
+class MessagesPublic(BaseModel):
+    data: list[MessageInfo]
+    count: int
+
+
+class PublishRequest(BaseModel):
+    value: Any
+    #: Where this came from, so the canvas can show it arriving from outside
+    #: rather than crediting whichever node is drawn as a producer.
+    source_kind: str = "api"
+    source_id: str = ""
+    source_label: str = ""
+    source_detail: str = ""
+
+
+class MessageValue(BaseModel):
+    name: str
+    value: Any
+    ts: float | None = None
+
+
+class MessagePoints(BaseModel):
+    message: str
+    numeric: bool
+    points: list[dict[str, float]]
+
+
+@router.get("/", response_model=MessagesPublic)
+async def read_messages(controller: FlowControllerDep) -> Any:
+    """Every message any published flow declares, with its last value."""
+    infos = await run_in_threadpool(controller.message_catalog)
+    return MessagesPublic(data=infos, count=len(infos))
+
+
+@router.post("/{name}", response_model=MessageValue)
+async def publish_message(
+    name: str, body: PublishRequest, controller: FlowControllerDep
+) -> Any:
+    """Put a value into the graph, as a dashboard control does.
+
+    Only a message some flow declares can be published to: flows own the
+    namespace, and a dashboard is a client of it rather than a second author.
+    """
+    source = ValueSource(
+        kind=body.source_kind,
+        id=body.source_id,
+        label=body.source_label or body.source_id or "API",
+        detail=body.source_detail,
+    )
+    try:
+        await run_in_threadpool(controller.publish_message, name, body.value, source)
+    except KeyError:
+        raise HTTPException(
+            status_code=404, detail=f"No flow declares a message named '{name}'"
+        )
+    except TypeError as exc:
+        raise HTTPException(status_code=422, detail=str(exc))
+
+    values = controller.values(flow_of(name))
+    current = values.get(name, {})
+    return MessageValue(name=name, value=current.get("value"), ts=current.get("ts"))
+
+
+@router.get("/{name}/history", response_model=MessagePoints)
+def read_message_history(name: str, controller: FlowControllerDep) -> Any:
+    """The series behind a chart. Numbers only — nothing else plots."""
+    if controller.pipeline is None:
+        return MessagePoints(message=name, numeric=False, points=[])
+    series = controller.state.history(name)
+    numeric = as_number(controller.state.get(name)) is not None
+    return MessagePoints(
+        message=name,
+        numeric=numeric or bool(series),
+        points=[{"ts": ts, "value": value} for ts, value in series],
+    )