initial: HarborForge plugin for Plexum (port of OpenclawPlugin)

Plugin id `harbor-forge` mirrors the OpenClaw counterpart's runtime
surface on top of the Plexum SDK:

  * eager activation — Monitor bridge + Calendar scheduler boot at
    host start, before any agent turn fires
  * monitor bridge: HTTP 127.0.0.1:<monitor_port> serving /telemetry
    + /health for HarborForge.Monitor
  * calendar scheduler: heartbeats <backendUrl>/calendar/agent/
    heartbeat, dispatches returned slots via HostAPI.WakeAgent
    (state-aware queue, depth-1 replace-newest), tracks active slot
    state in-memory, terminal status pushed back to backend
  * 9 harborforge_* tools (status / telemetry / monitor_telemetry /
    calendar_{status,complete,abort,pause,resume} / restart_status)

Key differences from OpenClaw equivalent:
  * api.spawn → HostAPI.WakeAgent (new SDK primitive)
  * api.getAgentStatus → HostAPI.ReadAgentState (existing)
  * --install-monitor / --install-cli not included; Monitor + hf CLI
    deploy via the HangmanLab.Server.T3 docker compose layer

Initial drop. TODO before v1 ship:
  * tool ctx → calling-agent-id: SDK doesn't currently expose; v1
    falls back to a single-active-slot heuristic in
    main.bestEffortAgentID
  * tests for the bridge + scheduler

scripts/install.sh

@@ -0,0 +1,48 @@
+#!/usr/bin/env bash
+# HarborForge.PlexumPlugin installer.
+set -euo pipefail
+
+REPO="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")/.." && pwd)"
+PROFILE_DIR="${HOME}/.plexum"
+
+while [[ $# -gt 0 ]]; do
+  case "$1" in
+    --profile) PROFILE_DIR="$2"; shift 2 ;;
+    -h|--help) sed -n '2,/^set -euo/p' "$0" | sed 's/^# \{0,1\}//'; exit 0 ;;
+    *) echo "unknown flag: $1" >&2; exit 2 ;;
+  esac
+done
+
+log() { printf '\033[1;34m[hf-install]\033[0m %s\n' "$*"; }
+command -v go >/dev/null || { echo "go not found on PATH" >&2; exit 1; }
+
+PLUGIN_DIR="${PROFILE_DIR}/plugins/harbor-forge"
+mkdir -p "${PLUGIN_DIR}"
+
+cd "${REPO}"
+VERSION="$(git describe --tags --always 2>/dev/null || echo dev)"
+LDFLAGS="-X main.Version=${VERSION}"
+log "building plexum-harborforge-plugin (v=${VERSION})"
+CGO_ENABLED=0 go build -ldflags="${LDFLAGS}" \
+  -o "${PLUGIN_DIR}/plexum-harborforge-plugin" \
+  ./cmd/plexum-harborforge-plugin
+
+cp manifest.json "${PLUGIN_DIR}/manifest.json"
+log "installed binary + manifest to ${PLUGIN_DIR}"
+
+cat <<EOF
+
+Next steps:
+  1. Add to ${PROFILE_DIR}/plexum.json .plugins.allow:
+       "harbor-forge"
+  2. Write ${PLUGIN_DIR}/config.json — sample:
+     {
+       "backendUrl": "https://monitor.hangman-lab.top",
+       "identifier": "server-t3",
+       "apiKey": "g1_xxx",
+       "monitor_port": 9100,
+       "calendar_enabled": true,
+       "calendar_heartbeat_interval_seconds": 30
+     }
+  3. Restart the host:  systemctl --user restart plexum
+EOF