initial drop: Dialectic.PlexumPlugin v0.1

Port of Dialectic.OpenclawPlugin to the Plexum SDK. 8 dialectic_*
tools wired to Dialectic.Backend over HTTP:

  list_topics, topic_detail, list_arguments, propose_topic,
  signup, post_argument, submit_verdict, view_verdict

Differences from the OpenClaw port worth noting:

  - Per-agent API key storage: OpenClaw used secret-mgr (one entry
    per agent's keyspace). Plexum has no secret-mgr; v1 stores
    keys directly in plugin config (apiKey + agentKeys map).

  - Agent identity at tool dispatch: OpenClaw framework surfaces
    ctx.agentId; Plexum SDK doesn't yet plumb the calling agent
    through ToolPlugin.CallTool. v1 falls back to
    config.defaultAgentID — same stop-gap HarborForge.PlexumPlugin
    is on. Tracked as upstream SDK work.

  - HF on_call coverage pre-check on signup: stub that always
    returns "skipped", matching OpenClaw v1's behavior (HarborForge
    never shipped the cross-plugin coverage query). pre_validated
    is sent as false so the backend records audit honestly.
    DIALECTIC_PLUGIN_BYPASS_HF=1 env retains parity with OpenClaw.

  - Activation: lazy (no background services, unlike HarborForge's
    eager-spawn for the calendar scheduler + monitor bridge).

Backend client follows the bearer-auth contract OpenClaw's
backend-client.ts established; endpoint shapes are unchanged.

cmd/plexum-dialectic-plugin/main.go

@@ -0,0 +1,96 @@
+// plexum-dialectic-plugin — Plexum-side Dialectic plugin.
+//
+// Ports Dialectic.OpenclawPlugin to the Plexum SDK: 8 dialectic_* tools
+// over HTTP against Dialectic.Backend. Lazy activation (no background
+// services — purely tool-call driven).
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	sdkplugin "git.hangman-lab.top/hzhang/Plexum-sdk-go/plugin"
+
+	dialcfg "git.hangman-lab.top/zhi/Dialectic.PlexumPlugin/internal/config"
+	"git.hangman-lab.top/zhi/Dialectic.PlexumPlugin/internal/tools"
+)
+
+var Version = "0.1.0"
+
+type dialecticPlugin struct {
+	host sdkplugin.HostAPI
+	cfg  dialcfg.Resolved
+	deps tools.Deps
+}
+
+func (p *dialecticPlugin) Manifest() sdkplugin.Manifest {
+	return manifestFromDisk()
+}
+
+func (p *dialecticPlugin) Init(ctx context.Context, host sdkplugin.HostAPI) error {
+	p.host = host
+
+	profileRoot := os.Getenv("PLEXUM_PROFILE_ROOT")
+	if profileRoot == "" {
+		home, _ := os.UserHomeDir()
+		profileRoot = filepath.Join(home, ".plexum")
+	}
+	raw, err := dialcfg.Load(profileRoot)
+	if err != nil {
+		return fmt.Errorf("load dialectic config: %w", err)
+	}
+	p.cfg = dialcfg.Resolve(raw)
+	host.Log("info", "dialectic plugin initialized", map[string]any{
+		"version":          Version,
+		"backend":          p.cfg.BackendURL,
+		"default_agent_id": p.cfg.DefaultAgentID,
+		"agent_keys_count": len(p.cfg.AgentKeys),
+		"has_default_key":  p.cfg.APIKey != "",
+	})
+
+	p.deps = tools.Deps{
+		Config: p.cfg,
+		Host:   host,
+		AgentIDFromCtx: func(ctx context.Context) string {
+			// v1: SDK doesn't surface the calling agent on tool ctx.
+			// Fall back to the per-claw default. Multi-agent claws will
+			// need SDK ctx plumbing — tracked upstream.
+			return p.cfg.DefaultAgentID
+		},
+	}
+	return nil
+}
+
+func (p *dialecticPlugin) CallTool(ctx context.Context, name string, input json.RawMessage) (sdkplugin.ToolResult, error) {
+	return tools.Dispatch(ctx, p.deps, name, input)
+}
+
+func manifestFromDisk() sdkplugin.Manifest {
+	exe, err := os.Executable()
+	if err == nil {
+		raw, err := os.ReadFile(filepath.Join(filepath.Dir(exe), "manifest.json"))
+		if err == nil {
+			var m sdkplugin.Manifest
+			if err := json.Unmarshal(raw, &m); err == nil && m.Name != "" {
+				return m
+			}
+		}
+	}
+	return sdkplugin.Manifest{
+		Name:       "dialectic",
+		Version:    Version,
+		Activation: sdkplugin.ActivationLazy,
+		Executable: "plexum-dialectic-plugin",
+	}
+}
+
+func main() {
+	if err := sdkplugin.Serve(&dialecticPlugin{}); err != nil && !errors.Is(err, context.Canceled) {
+		fmt.Fprintf(os.Stderr, "plexum-dialectic-plugin: %v\n", err)
+		os.Exit(1)
+	}
+}