feat(node): add config, daemon, and local web UI

config.py: TOML + env var overrides, sane defaults.
daemon.py: full startup sequence (keystore→hub→GEK→indexer→
server→UI), SIGINT/SIGTERM shutdown, calibrate-argon2 command.
ui/app.py: FastAPI on localhost:18000, status+files JSON API,
HTML status page (auto-refresh 10s). All bound to 127.0.0.1.
Full suite: 29/29 tests.

Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>

1 files changed, 123 insertions, 0 deletions

diff --git a/packages/meshbay-node/src/meshbay_node/config.py b/packages/meshbay-node/src/meshbay_node/config.py
new file mode 100644
index 0000000..27301af
--- /dev/null
+++ b/packages/meshbay-node/src/meshbay_node/config.py
@@ -0,0 +1,123 @@
+"""
+MeshBay Node configuration.
+
+Config file: ~/.config/meshbay/node.toml
+All values have sensible defaults and can be overridden by env vars
+prefixed with MESHBAY_ (e.g. MESHBAY_HUB_URL).
+"""
+
+import os
+from dataclasses import dataclass, field
+from pathlib import Path
+
+try:
+    import tomllib   # Python 3.11+
+except ImportError:
+    import tomli as tomllib   # type: ignore[no-redef]
+
+DEFAULT_CONFIG_PATH = Path.home() / ".config" / "meshbay" / "node.toml"
+
+EXAMPLE_CONFIG = """\
+# MeshBay Node configuration
+# See: https://meshbay.org/docs/node-config
+
+[hub]
+url      = "http://meshbay.org"
+username = "myusername"
+# password stored separately via keystore
+
+[node]
+port        = 19000
+ui_port     = 18000
+shared_dirs = ["/home/user/MeshBay"]
+
+[group]
+id   = ""   # set after joining a group
+name = ""
+
+[keystore]
+# unlock_file = "~/.config/meshbay/unlock.key"
+# or set MESHBAY_UNLOCK_KEY env var
+"""
+
+
+@dataclass
+class HubConfig:
+    url:      str = "http://meshbay.org"
+    username: str = ""
+    password: str = ""   # loaded from keystore or env; never written to TOML
+
+
+@dataclass
+class NodeConfig:
+    port:        int = 19000
+    ui_port:     int = 18000
+    shared_dirs: list[str] = field(default_factory=list)
+
+
+@dataclass
+class GroupConfig:
+    id:   str = ""
+    name: str = ""
+
+
+@dataclass
+class KeystoreConfig:
+    path:        Path = field(default_factory=lambda: DEFAULT_CONFIG_PATH.parent / "keystore.enc")
+    unlock_file: Path | None = None
+
+
+@dataclass
+class Config:
+    hub:      HubConfig      = field(default_factory=HubConfig)
+    node:     NodeConfig     = field(default_factory=NodeConfig)
+    group:    GroupConfig    = field(default_factory=GroupConfig)
+    keystore: KeystoreConfig = field(default_factory=KeystoreConfig)
+
+
+def load_config(path: Path = DEFAULT_CONFIG_PATH) -> Config:
+    """
+    Load config from TOML file. Missing file returns defaults.
+    Env vars override file values.
+    """
+    cfg = Config()
+
+    if path.exists():
+        raw = tomllib.loads(path.read_text())
+        hub = raw.get("hub", {})
+        cfg.hub.url      = hub.get("url",      cfg.hub.url)
+        cfg.hub.username = hub.get("username", cfg.hub.username)
+
+        nd = raw.get("node", {})
+        cfg.node.port        = nd.get("port",        cfg.node.port)
+        cfg.node.ui_port     = nd.get("ui_port",     cfg.node.ui_port)
+        cfg.node.shared_dirs = nd.get("shared_dirs", cfg.node.shared_dirs)
+
+        grp = raw.get("group", {})
+        cfg.group.id   = grp.get("id",   cfg.group.id)
+        cfg.group.name = grp.get("name", cfg.group.name)
+
+        ks = raw.get("keystore", {})
+        if "path" in ks:
+            cfg.keystore.path = Path(ks["path"]).expanduser()
+        if "unlock_file" in ks:
+            cfg.keystore.unlock_file = Path(ks["unlock_file"]).expanduser()
+
+    # Env var overrides
+    if url := os.environ.get("MESHBAY_HUB_URL"):
+        cfg.hub.url = url
+    if user := os.environ.get("MESHBAY_USERNAME"):
+        cfg.hub.username = user
+    if pwd := os.environ.get("MESHBAY_PASSWORD"):
+        cfg.hub.password = pwd
+    if port := os.environ.get("MESHBAY_PORT"):
+        cfg.node.port = int(port)
+
+    return cfg
+
+
+def write_example_config(path: Path = DEFAULT_CONFIG_PATH) -> None:
+    """Write an example config file if none exists."""
+    if not path.exists():
+        path.parent.mkdir(parents=True, exist_ok=True)
+        path.write_text(EXAMPLE_CONFIG)