Add agentpr and watchpr CLI tools

agentpr manages PRs/comments/whoami as unkin-agent (Vault AppRole -> gitea creds
-> Gitea API), fixing tea's post-as-Ben default. watchpr polls PRs and alerts
only on merge/close, human comment, CI failure, or lost mergeability.

- cobra multi-binary layout mirroring node-lookup (cmd/ + internal/)
- Makefile (build, patch|minor|major, completions, rpm), nfpm RPM with both
  binaries + bash/zsh/fish completions, woodpecker CI publishing to rpm-internal
- unit tests for parsing, meaningful-change detection, and the Vault+Gitea client

internal/agent/parse_test.go

@@ -0,0 +1,79 @@
+package agent
+
+import "testing"
+
+func TestParsePRRef(t *testing.T) {
+	tests := []struct {
+		in      string
+		wantErr bool
+		owner   string
+		repo    string
+		num     int
+	}{
+		{"unkin/argocd-apps#42", false, "unkin", "argocd-apps", 42},
+		{"unkin/argocd-apps:42", false, "unkin", "argocd-apps", 42},
+		{"  unkin/repo#1  ", false, "unkin", "repo", 1},
+		{"unkin/repo#0", true, "", "", 0},
+		{"unkin/repo#-3", true, "", "", 0},
+		{"unkin/repo#abc", true, "", "", 0},
+		{"unkin/repo", true, "", "", 0},
+		{"unkinrepo#3", true, "", "", 0},
+		{"unkin/a/b#3", true, "", "", 0},
+		{"/repo#3", true, "", "", 0},
+		{"unkin/#3", true, "", "", 0},
+	}
+	for _, tt := range tests {
+		got, err := ParsePRRef(tt.in)
+		if tt.wantErr {
+			if err == nil {
+				t.Errorf("ParsePRRef(%q): expected error, got %+v", tt.in, got)
+			}
+			continue
+		}
+		if err != nil {
+			t.Errorf("ParsePRRef(%q): unexpected error: %v", tt.in, err)
+			continue
+		}
+		if got.Owner != tt.owner || got.Repo != tt.repo || got.Number != tt.num {
+			t.Errorf("ParsePRRef(%q) = %+v, want %s/%s#%d", tt.in, got, tt.owner, tt.repo, tt.num)
+		}
+	}
+}
+
+func TestPRRefString(t *testing.T) {
+	r := PRRef{Owner: "unkin", Repo: "repo", Number: 7}
+	if got := r.String(); got != "unkin/repo#7" {
+		t.Errorf("String() = %q, want unkin/repo#7", got)
+	}
+	if got := r.RepoPath(); got != "unkin/repo" {
+		t.Errorf("RepoPath() = %q, want unkin/repo", got)
+	}
+}
+
+func TestParseRepo(t *testing.T) {
+	tests := []struct {
+		in      string
+		wantErr bool
+		owner   string
+		repo    string
+	}{
+		{"unkin/repo", false, "unkin", "repo"},
+		{" unkin/repo ", false, "unkin", "repo"},
+		{"repo", true, "", ""},
+		{"unkin/a/b", true, "", ""},
+		{"/repo", true, "", ""},
+		{"unkin/", true, "", ""},
+	}
+	for _, tt := range tests {
+		o, r, err := ParseRepo(tt.in)
+		if tt.wantErr {
+			if err == nil {
+				t.Errorf("ParseRepo(%q): expected error", tt.in)
+			}
+			continue
+		}
+		if err != nil || o != tt.owner || r != tt.repo {
+			t.Errorf("ParseRepo(%q) = (%q,%q,%v), want (%q,%q,nil)", tt.in, o, r, err, tt.owner, tt.repo)
+		}
+	}
+}