feat(plugins): fold first-party plugins in-tree; bundled + external roots

First-party plugins (host_agent, http, snmp, traefik, unifi, docker) are now
tracked under plugins/ and baked into the image, so they version atomically
with core — ending the cross-repo import drift the roundtable->steward rename
exposed. History for these files is preserved in the archived Roundtable-plugins
repo.

Plugin discovery becomes multi-root: PLUGIN_DIR (single) -> PLUGIN_DIRS
(bundled first, then external) + PLUGIN_INSTALL_DIR. Bundled ships in the image;
third-party plugins still mount at runtime into the external root
(STEWARD_PLUGIN_DIR, default /data/plugins) and downloads/installs land there.
Bundled shadows external on a name collision.

- config.py: load_bootstrap returns plugin_dirs + plugin_install_dir
- app.py: iterate PLUGIN_DIRS at the migration + load sites
- migration_runner.py: discover_all_in() unions every plugin root
- plugin_manager.py: resolve_plugin_path() (pure, first-root-wins); load /
  install / hot-reload span all roots; installs target the external root
- settings/routes.py: _discover_plugins scans all roots, dedup bundled-first
- Dockerfile: COPY plugins/ ; docker-compose: drop host bind, document external
- tests/test_plugin_dirs.py: resolution, multi-root discovery, bootstrap split

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

plugins/snmp/routes.py

@@ -0,0 +1,146 @@
+# plugins/snmp/routes.py
+from __future__ import annotations
+from datetime import datetime, timedelta, timezone
+
+from quart import Blueprint, current_app, render_template, request
+from sqlalchemy import func, select
+
+from fabledscryer.auth.middleware import require_role
+from fabledscryer.models.users import UserRole
+from fabledscryer.models.metrics import PluginMetric
+
+snmp_bp = Blueprint("snmp", __name__, template_folder="templates")
+
+
+async def _latest_readings(db, device_names: list[str]) -> dict[str, dict[str, float]]:
+    """Return {device_name: {label: latest_value}} for all configured devices."""
+    if not device_names:
+        return {}
+
+    # Latest value per (resource_name, metric_name) pair
+    subq = (
+        select(
+            PluginMetric.resource_name,
+            PluginMetric.metric_name,
+            func.max(PluginMetric.recorded_at).label("latest_at"),
+        )
+        .where(PluginMetric.source_module == "snmp")
+        .where(PluginMetric.resource_name.in_(device_names))
+        .group_by(PluginMetric.resource_name, PluginMetric.metric_name)
+        .subquery()
+    )
+    result = await db.execute(
+        select(PluginMetric).join(
+            subq,
+            (PluginMetric.resource_name == subq.c.resource_name)
+            & (PluginMetric.metric_name == subq.c.metric_name)
+            & (PluginMetric.recorded_at == subq.c.latest_at),
+        ).where(PluginMetric.source_module == "snmp")
+    )
+    rows = result.scalars().all()
+
+    out: dict[str, dict[str, float]] = {}
+    for row in rows:
+        out.setdefault(row.resource_name, {})[row.metric_name] = row.value
+    return out
+
+
+async def _history(db, device_name: str, hours: int = 24) -> dict[str, list]:
+    """Return {label: [(recorded_at, value), ...]} for a single device."""
+    since = datetime.now(timezone.utc) - timedelta(hours=hours)
+    result = await db.execute(
+        select(PluginMetric)
+        .where(
+            PluginMetric.source_module == "snmp",
+            PluginMetric.resource_name == device_name,
+            PluginMetric.recorded_at >= since,
+        )
+        .order_by(PluginMetric.recorded_at)
+    )
+    rows = result.scalars().all()
+
+    out: dict[str, list] = {}
+    for row in rows:
+        out.setdefault(row.metric_name, []).append(
+            (row.recorded_at.isoformat(), row.value)
+        )
+    return out
+
+
+@snmp_bp.get("/")
+@require_role(UserRole.viewer)
+async def index():
+    devices_cfg: list[dict] = current_app.config["PLUGINS"]["snmp"].get("devices", [])
+    device_names = [d.get("name") or d.get("host", "?") for d in devices_cfg]
+
+    async with current_app.db_sessionmaker() as db:
+        latest = await _latest_readings(db, device_names)
+
+    # Merge config + latest readings for the template
+    devices = []
+    for cfg in devices_cfg:
+        name = cfg.get("name") or cfg.get("host", "?")
+        devices.append({
+            "name": name,
+            "host": cfg.get("host", ""),
+            "oids": cfg.get("oids", []),
+            "readings": latest.get(name, {}),
+        })
+
+    poll_interval = current_app.config.get("MONITORS_POLL_INTERVAL", 60)
+    return await render_template("snmp/index.html",
+                                 devices=devices,
+                                 poll_interval=poll_interval)
+
+
+@snmp_bp.get("/widget")
+@require_role(UserRole.viewer)
+async def widget():
+    devices_cfg: list[dict] = current_app.config["PLUGINS"]["snmp"].get("devices", [])
+    device_names = [d.get("name") or d.get("host", "?") for d in devices_cfg]
+
+    async with current_app.db_sessionmaker() as db:
+        latest = await _latest_readings(db, device_names[:10])
+
+    devices = []
+    for cfg in devices_cfg[:10]:
+        name = cfg.get("name") or cfg.get("host", "?")
+        devices.append({
+            "name": name,
+            "oids": cfg.get("oids", []),
+            "readings": latest.get(name, {}),
+        })
+
+    return await render_template("snmp/widget.html",
+                                 devices=devices,
+                                 total=len(devices_cfg))
+
+
+@snmp_bp.get("/device/<device_name>")
+@require_role(UserRole.viewer)
+async def device_detail(device_name: str):
+    devices_cfg: list[dict] = current_app.config["PLUGINS"]["snmp"].get("devices", [])
+    device_cfg = next(
+        (d for d in devices_cfg if (d.get("name") or d.get("host")) == device_name),
+        None,
+    )
+    if device_cfg is None:
+        from quart import abort
+        abort(404)
+
+    hours = int(request.args.get("hours", 24))
+    async with current_app.db_sessionmaker() as db:
+        hist = await _history(db, device_name, hours=hours)
+
+    import json
+    history_json = json.dumps(hist)
+    oid_labels = [o.get("label") or o.get("oid") for o in device_cfg.get("oids", [])]
+
+    return await render_template(
+        "snmp/device.html",
+        device=device_cfg,
+        device_name=device_name,
+        oid_labels=oid_labels,
+        history_json=history_json,
+        hours=hours,
+    )