homelab: v0.6.0 — usage telemetry (usage top), evidence-driven verb prioritization

Answers the question that drove the whole CLI — which verbs to add next — with
data instead of one maintainer's habits, and resolves the cross-user-usage ask
in-bounds (no reading anyone's home).

- emit on dispatch: every verb fire-and-forgets one Loki line {job,user,verb} +
  "exit=N ver=X". ONLY the verb path + exit code — never args, paths, flags, or
  secrets (the emit never sees arguments). Best-effort: 800ms timeout, errors
  swallowed, never affects the command; opt-out HOMELAB_TELEMETRY=0. Discovery
  verbs (manifest/version/help) and usage itself don't self-record.
- usage top [--since 30d] [--user U] [--json]: ranks verbs via
  sum by (verb)(count_over_time({job="homelab-usage"}[…])) against the shared
  Loki. Cross-user analytics WITHOUT touching ~/.claude — the privacy-preserving
  answer to "what does the team use".
- Loki sink (zero new infra, dogfoods v0.5 logs path); push verified HTTP 204 no
  auth. ADR docs/adr/0011.

Live-verified: ran 4 verbs, usage top ranked them correctly (metrics query=2).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

cli/cmd_usage.go

@@ -0,0 +1,77 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/url"
+	"sort"
+	"strconv"
+)
+
+func usageCommands() []Command {
+	return []Command{
+		{Path: []string{"usage", "top"}, Tier: TierRead,
+			Summary: "rank homelab verb usage across users (from Loki): usage top [--since 30d] [--user U] [--json]", Run: usageTop},
+	}
+}
+
+// usageQuery builds the LogQL metric query that counts invocations per verb.
+func usageQuery(since, user string) string {
+	sel := `job="` + usageJob + `"`
+	if user != "" {
+		sel += `, user="` + user + `"`
+	}
+	return fmt.Sprintf(`sum by (verb) (count_over_time({%s}[%s]))`, sel, since)
+}
+
+func usageTop(args []string) error {
+	since := flagValue(args, "--since")
+	if since == "" {
+		since = "30d"
+	}
+	v := url.Values{}
+	v.Set("query", usageQuery(since, flagValue(args, "--user")))
+	body, err := lbGetBody(lokiHost, "/loki/api/v1/query", v)
+	if err != nil {
+		return err
+	}
+	if containsArg(args, "--json") {
+		fmt.Println(string(body))
+		return nil
+	}
+	var r struct {
+		Data struct {
+			Result []struct {
+				Metric map[string]string `json:"metric"`
+				Value  []interface{}     `json:"value"`
+			} `json:"result"`
+		} `json:"data"`
+	}
+	if err := json.Unmarshal(body, &r); err != nil {
+		fmt.Println(string(body))
+		return nil
+	}
+	type row struct {
+		verb string
+		n    int
+	}
+	var rows []row
+	for _, s := range r.Data.Result {
+		n := 0
+		if len(s.Value) == 2 {
+			if f, e := strconv.ParseFloat(fmt.Sprint(s.Value[1]), 64); e == nil {
+				n = int(f)
+			}
+		}
+		rows = append(rows, row{s.Metric["verb"], n})
+	}
+	if len(rows) == 0 {
+		fmt.Println("(no usage recorded yet)")
+		return nil
+	}
+	sort.Slice(rows, func(i, j int) bool { return rows[i].n > rows[j].n })
+	for _, r := range rows {
+		fmt.Printf("%6d  %s\n", r.n, r.verb)
+	}
+	return nil
+}