feat(agentnetwork): adjective-noun subdomain label generation

Adds PickTuple, which draws an adjective and a noun to form a single DNS
label such as "brave-otter". The existing single-word generator kept a
per-cluster "taken" set and guessed uniqueness up front; a later commit
replaces that with a database constraint and a retry, so PickTuple
deliberately takes no taken set and has no fallback suffix.

The adjectives live in their own pool rather than reusing the noun list,
which is almost entirely nouns -- drawing twice from it produces
"millet-hammock", which reads as noise rather than a name. Tests assert the
curation contract the pool depends on: duplicate-free, DNS-safe, and
disjoint from the nouns.

management/internals/modules/agentnetwork/labelgen/adjectives.go

@@ -0,0 +1,39 @@
+// Package labelgen produces DNS-safe Agent Network subdomain labels.
+//
+// The adjective pool below pairs with the noun pool in words.go to form
+// `<adjective>-<noun>` labels. It is kept separate because words.go is almost
+// entirely nouns — drawing both halves from it produced unreadable pairs like
+// "millet-hammock". Entries are lowercase ASCII, 4-12 chars, free of hyphens
+// and digits, screened for offensive/brand/region-specific terms, and disjoint
+// from the noun pool (enforced by TestAdjectives_AreDisjointFromNouns).
+package labelgen
+
+// adjectives is the descriptor half of a generated label.
+var adjectives = []string{
+	"able", "active", "adept", "agile", "airy", "alert", "amiable", "ample",
+	"ancient", "ardent", "artful", "astute", "balmy", "blithe", "bold", "bonny",
+	"brave", "breezy", "brisk", "bubbly", "buoyant", "bushy", "candid", "canny",
+	"cheery", "chilly", "chipper", "chunky", "civil", "classic", "clever", "comely",
+	"compact", "cordial", "cosmic", "courtly", "crafty", "creamy", "crisp", "cuddly",
+	"curious", "dainty", "dapper", "daring", "dashing", "deft", "dewy", "diligent",
+	"downy", "dreamy", "dulcet", "durable", "dusky", "eager", "earnest", "earthy",
+	"easy", "elated", "elegant", "epic", "fabled", "faithful", "fancy", "fearless",
+	"feisty", "fervent", "fleet", "fluffy", "fond", "frisky", "frosty", "gallant",
+	"genial", "genteel", "gentle", "giddy", "gilded", "glad", "glassy", "gleaming",
+	"glossy", "graceful", "grand", "grainy", "hale", "hardy", "hearty", "hefty",
+	"honest", "hopeful", "humble", "hushed", "immense", "jaunty", "jolly", "jovial",
+	"joyful", "jubilant", "keen", "kindly", "kindred", "lanky", "leafy", "limber",
+	"lively", "lofty", "loyal", "lucent", "lucid", "luminous", "lush", "maroon",
+	"mellow", "merry", "mighty", "mindful", "mirthful", "misty", "modest", "muted",
+	"nifty", "nimble", "noble", "patient", "peaceful", "pearly", "peppy", "perky",
+	"petite", "placid", "playful", "pleasant", "plucky", "plush", "polite", "posh",
+	"prancing", "pristine", "prompt", "proud", "prudent", "quaint", "quick", "quirky",
+	"radiant", "ready", "regal", "restful", "robust", "rosy", "ruddy", "rugged",
+	"sandy", "satin", "saucy", "savvy", "sedate", "serene", "shady", "shiny",
+	"silken", "silky", "sincere", "sleek", "slender", "smart", "smooth", "snappy",
+	"snug", "soaring", "sparkly", "spiffy", "spirited", "sprightly", "spry", "stalwart",
+	"stately", "steady", "sterling", "stoic", "stormy", "stout", "sturdy", "sunlit",
+	"supple", "svelte", "tawny", "tender", "tidy", "timeless", "trusty", "upbeat",
+	"urbane", "valiant", "vast", "vernal", "vibrant", "vintage", "whimsy", "willing",
+	"windy", "winsome", "wintry", "witty", "worthy", "zesty", "zippy",
+}

management/internals/modules/agentnetwork/labelgen/labelgen.go

@@ -64,3 +64,20 @@ func PickUnique(rng *rand.Rand, taken map[string]struct{}, fallbackSuffix string
 	w := pool[rng.Intn(len(pool))]
 	return fmt.Sprintf("%s-%s", w, fallbackSuffix)
 }
+
+// PickTuple returns an adjective-noun label such as "brave-otter". It is still
+// a single DNS label.
+//
+// Unlike PickUnique it takes no `taken` set and has no fallback suffix. The
+// noun pool holds 857 entries, which is ample per cluster but a hard ceiling
+// once labels must be unique across one shared zone; pairing an adjective with
+// a noun spans len(adjectives) * 857 instead. Uniqueness is enforced by a
+// database constraint and retried by the caller, rather than guessed from a
+// pre-read set that a concurrent allocation can invalidate.
+func PickTuple(rng *rand.Rand) string {
+	nouns := uniqueWords()
+	if len(nouns) == 0 || len(adjectives) == 0 {
+		return ""
+	}
+	return adjectives[rng.Intn(len(adjectives))] + "-" + nouns[rng.Intn(len(nouns))]
+}

management/internals/modules/agentnetwork/labelgen/labelgen_test.go

@@ -99,3 +99,82 @@ func TestUniqueWords_DropsDuplicates(t *testing.T) {
 	}
 	assert.GreaterOrEqual(t, len(pool), 500, "Pool must contain at least 500 unique words")
 }
+
+// TestPickTuple_ShapeAndPoolMembership locks the wire-visible shape: an
+// adjective and a noun, each from its own pool, joined by a single hyphen so
+// the result stays one DNS label.
+func TestPickTuple_ShapeAndPoolMembership(t *testing.T) {
+	nouns := uniqueWords()
+	inNouns := make(map[string]struct{}, len(nouns))
+	for _, w := range nouns {
+		inNouns[w] = struct{}{}
+	}
+	inAdjectives := make(map[string]struct{}, len(adjectives))
+	for _, a := range adjectives {
+		inAdjectives[a] = struct{}{}
+	}
+
+	rng := rand.New(rand.NewSource(7))
+	for i := 0; i < 200; i++ {
+		got := PickTuple(rng)
+
+		parts := strings.Split(got, "-")
+		require.Len(t, parts, 2, "PickTuple must produce exactly two hyphen-joined words; got %q", got)
+
+		_, adjOK := inAdjectives[parts[0]]
+		assert.True(t, adjOK, "First half must be an adjective; %q not in adjectives (from %q)", parts[0], got)
+		_, nounOK := inNouns[parts[1]]
+		assert.True(t, nounOK, "Second half must be a noun; %q not in words (from %q)", parts[1], got)
+
+		assert.LessOrEqual(t, len(got), 63, "Label must fit a DNS label; got %q (%d chars)", got, len(got))
+	}
+}
+
+// TestAdjectives_AreDisjointFromNouns keeps the namespace a clean product and
+// prevents nonsense like "azure-azure": a handful of the noun pool's entries
+// are adjectival, and any overlap would let the same word land on both sides.
+func TestAdjectives_AreDisjointFromNouns(t *testing.T) {
+	nouns := make(map[string]struct{}, len(uniqueWords()))
+	for _, w := range uniqueWords() {
+		nouns[w] = struct{}{}
+	}
+	for _, a := range adjectives {
+		_, clash := nouns[a]
+		assert.False(t, clash, "Adjective %q also appears in the noun pool; remove it from one list", a)
+	}
+}
+
+// TestAdjectives_AreDNSSafeAndDeduplicated mirrors the curation contract stated
+// in words.go: lowercase ASCII, 4-12 chars, no digits or hyphens, no repeats.
+func TestAdjectives_AreDNSSafeAndDeduplicated(t *testing.T) {
+	seen := make(map[string]struct{}, len(adjectives))
+	for _, a := range adjectives {
+		_, dup := seen[a]
+		assert.False(t, dup, "Duplicate adjective %q", a)
+		seen[a] = struct{}{}
+
+		assert.Regexp(t, `^[a-z]{4,12}$`, a, "Adjective %q must be 4-12 lowercase ASCII letters", a)
+	}
+	assert.Greater(t, len(adjectives), 150, "Adjective pool too small to give a useful namespace")
+}
+
+// TestPickTuple_DeterministicWithSeededRng documents that generation is a pure
+// function of the rng, which is what makes allocation retries reproducible in tests.
+func TestPickTuple_DeterministicWithSeededRng(t *testing.T) {
+	a := PickTuple(rand.New(rand.NewSource(42)))
+	b := PickTuple(rand.New(rand.NewSource(42)))
+	assert.Equal(t, a, b, "Same seed must yield the same tuple")
+}
+
+// TestPickTuple_SpansALargeNamespace guards the reason we moved to tuples: a
+// single-word pool caps the GLOBAL namespace at 857. Drawing many tuples must
+// yield overwhelmingly distinct values.
+func TestPickTuple_SpansALargeNamespace(t *testing.T) {
+	rng := rand.New(rand.NewSource(11))
+	seen := make(map[string]struct{}, 2000)
+	for i := 0; i < 2000; i++ {
+		seen[PickTuple(rng)] = struct{}{}
+	}
+	assert.Greater(t, len(seen), 1900,
+		"2000 draws should be nearly all distinct across a ~200k namespace; got %d unique", len(seen))
+}