diff --git a/CHANGELOG.md b/CHANGELOG.md
index 53186838..acf2f7b5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,11 +8,12 @@ Format: [Keep a Changelog](https://keepachangelog.com/en/1.0.0/) · Versioning:
 ## [Unreleased]
 
 ### Changed
-- **Renamed host product references from hawk to rho.** Host config paths
-  (`~/.rho/`), the `rho_build`/`rho_build_concise` tool namespaces, the
-  `rho_response` schema name, and the `EXPORT_RHO_FIXTURE` env var now use the
-  rho identity. Retired ecosystem repos (`shrike`, `harrier`, `kestrel`,
-  `merlin`) are no longer referenced.
+- **Renamed host product references to rho.** Host config paths (`~/.rho/`),
+  the `rho_build`/`rho_build_concise` tool namespaces, the `rho_response`
+  schema name, and the `EXPORT_RHO_FIXTURE` env var now use the rho identity.
+  References to retired ecosystem repos were removed.
+- **Credential env-file migration falls back to the pre-rename host config
+  directory** so installs created before the rename still migrate.
 
 ## [0.0.1] — 2026-09-15
 
diff --git a/README.md b/README.md
index 033dbb8e..c6ad2a70 100644
--- a/README.md
+++ b/README.md
@@ -63,7 +63,6 @@ and two Go AST tests in `rho/internal/testaudit/`.
 
 - do not import `rho/internal/*`
 - do not import the removed legacy path `rho/shared/types`
-- do not import other engines (`swift`) — engines are peers, not dependencies
 
 ## Quick Start
 
@@ -320,7 +319,6 @@ flux is part of the graycode-eco:
 |---|---|---|
 | **rho** | [GrayCodeAI/rho](https://github.com/GrayCodeAI/rho) | AI coding agent |
 | **flux** | This repo | LLM provider runtime |
-| **swift** | [GrayCodeAI/swift](https://github.com/GrayCodeAI/swift) | Session capture |
 
 ## Development
 
diff --git a/credentials/migrate.go b/credentials/migrate.go
index 233f40d5..954450e9 100644
--- a/credentials/migrate.go
+++ b/credentials/migrate.go
@@ -25,7 +25,9 @@ func markEnvFileMigrationDone() {
 }
 
 // MigrateEnvFileCredentials imports API keys from plaintext credential files
-// (~/.rho/env, ~/.rho/.env) into the OS secret store and removes them.
+// (~/.rho/env, ~/.rho/.env) into the OS secret store and removes them. It also
+// checks the pre-rename host config directory (~/.hawk/env, ~/.hawk/.env) so
+// installs created before the rename still migrate.
 func MigrateEnvFileCredentials(ctx context.Context) (int, error) {
 	if ctx == nil {
 		ctx = context.Background()
@@ -34,7 +36,7 @@ func MigrateEnvFileCredentials(ctx context.Context) (int, error) {
 		return 0, nil
 	}
 	total := 0
-	for _, path := range []string{rhoEnvPath(), rhoDotEnvPath()} {
+	for _, path := range []string{rhoEnvPath(), rhoDotEnvPath(), legacyEnvPath(), legacyDotEnvPath()} {
 		n, err := migrateEnvFileAt(ctx, path)
 		if err != nil && !os.IsNotExist(err) {
 			return total, err
@@ -93,6 +95,19 @@ func rhoDotEnvPath() string {
 	return filepath.Join(home, ".rho", ".env")
 }
 
+// legacyEnvPath is the pre-rename host config file path, kept so installs
+// created before the rename still migrate.
+func legacyEnvPath() string {
+	home, _ := os.UserHomeDir()
+	return filepath.Join(home, ".hawk", "env")
+}
+
+// legacyDotEnvPath is the pre-rename host dotenv file path.
+func legacyDotEnvPath() string {
+	home, _ := os.UserHomeDir()
+	return filepath.Join(home, ".hawk", ".env")
+}
+
 func readEnvFile(path string) (map[string]string, error) {
 	data, err := os.ReadFile(path) // #nosec G304 -- path is built from os.UserHomeDir() in rhoDotEnvPath, not untrusted input
 	if err != nil {
diff --git a/credentials/migrate_test.go b/credentials/migrate_test.go
index d02887e0..70c33681 100644
--- a/credentials/migrate_test.go
+++ b/credentials/migrate_test.go
@@ -311,6 +311,37 @@ func TestMigrateEnvFileCredentials_BothPaths(t *testing.T) {
 	}
 }
 
+func TestMigrateEnvFileCredentials_LegacyPaths(t *testing.T) {
+	ms := &MapStore{}
+	cs := &CombinedStore{Keychain: ms}
+	SetDefaultStore(cs)
+	t.Cleanup(func() { SetDefaultStore(nil) })
+
+	dir := t.TempDir()
+	t.Setenv("HOME", dir)
+
+	legacyDir := filepath.Join(dir, ".hawk")
+	if err := os.MkdirAll(legacyDir, 0o700); err != nil {
+		t.Fatal(err)
+	}
+	envPath := filepath.Join(legacyDir, "env")
+	if err := os.WriteFile(envPath, []byte("ANTHROPIC_API_KEY=sk-legacy\n"), 0o600); err != nil {
+		t.Fatal(err)
+	}
+
+	ctx := context.Background()
+	n, err := MigrateEnvFileCredentials(ctx)
+	if err != nil {
+		t.Fatalf("error: %v", err)
+	}
+	if n != 1 {
+		t.Fatalf("expected 1 migrated from legacy path, got %d", n)
+	}
+	if _, err := os.Stat(envPath); !os.IsNotExist(err) {
+		t.Error("legacy ~/.hawk/env should be removed after migration")
+	}
+}
+
 func TestMigrateEnvFileCredentialsAt_NilKeychain(t *testing.T) {
 	// When DefaultStore is a CombinedStore with nil Keychain, migration should fail.
 	cs := &CombinedStore{Keychain: nil}
diff --git a/docs/guides/CREDENTIAL-SETUP-FLOW.md b/docs/guides/CREDENTIAL-SETUP-FLOW.md
index c999d485..b38c809c 100644
--- a/docs/guides/CREDENTIAL-SETUP-FLOW.md
+++ b/docs/guides/CREDENTIAL-SETUP-FLOW.md
@@ -69,7 +69,7 @@ Setup is **gateway-first**: pick the gateway on the Gateways tab, paste any non-
   → Pick model    → ListModels (auto) when credentials exist
 ```
 
-## Host API (rho uses `internal/fluxclient` only)
+## Host API (rho integrates through `flux/engine`)
 
 - `ResolveCredentialForHost` / `SaveCredentialForHost`
 - `ApplyFluxCredentials`
diff --git a/internal/observability/genai_semconv.go b/internal/observability/genai_semconv.go
index a7048ead..bb53f7a9 100644
--- a/internal/observability/genai_semconv.go
+++ b/internal/observability/genai_semconv.go
@@ -3,7 +3,7 @@
 // These exported constants are the canonical, ecosystem-wide attribute keys for
 // describing LLM / AI agent operations. They follow the OpenTelemetry GenAI
 // semantic conventions (gen_ai.*) and are shared as the reference set that the
-// other graycode-eco repos (rho, swift) should mirror when emitting
+// other graycode-eco repos should mirror when emitting
 // spans, so dashboards and exporters can correlate cost/usage/identity across
 // the whole ecosystem.
 //
diff --git a/scripts/check-ecosystem-boundaries.sh b/scripts/check-ecosystem-boundaries.sh
index a40d9eba..dc51e3fc 100755
--- a/scripts/check-ecosystem-boundaries.sh
+++ b/scripts/check-ecosystem-boundaries.sh
@@ -8,16 +8,11 @@ cd "$ROOT_DIR"
 # Shared ecosystem vocabulary lives in rho/internal/contracts, which
 # hosts vendor rather than import from here.
 FORBIDDEN_RHO='github\.com/GrayCodeAI/rho(/|")'
-FORBIDDEN_ENGINES='github\.com/GrayCodeAI/swift(/|")'
-
-exit_code=0
 
 if command -v rg >/dev/null 2>&1; then
   violations="$(rg -n "$FORBIDDEN_RHO" --glob '*.go' . || true)"
-  engine_violations="$(rg -n "$FORBIDDEN_ENGINES" --glob '*.go' . || true)"
 else
   violations="$(grep -rn --include='*.go' -E "$FORBIDDEN_RHO" . || true)"
-  engine_violations="$(grep -rn --include='*.go' -E "$FORBIDDEN_ENGINES" . || true)"
 fi
 
 if [[ -n "${violations}" ]]; then
@@ -25,19 +20,7 @@ if [[ -n "${violations}" ]]; then
   echo "${violations}"
   echo
   echo "flux must use local contracts, never the Rho product module"
-  exit_code=1
-fi
-
-if [[ -n "${engine_violations}" ]]; then
-  echo "forbidden cross-engine imports found:"
-  echo "${engine_violations}"
-  echo
-  echo "support engines must not import other engines directly — they are peers, not dependencies"
-  exit_code=1
-fi
-
-if [[ $exit_code -ne 0 ]]; then
-  exit $exit_code
+  exit 1
 fi
 
-echo "ecosystem boundary guard passed"
+echo "ecosystem boundary guard passed"
\ No newline at end of file
diff --git a/tools/versioning.go b/tools/versioning.go
index 18882f08..67b2be73 100644
--- a/tools/versioning.go
+++ b/tools/versioning.go
@@ -33,7 +33,7 @@ func BehaviorPresetFrom(s string) (BehaviorPreset, error) {
 }
 
 // FinalizeErrorCode classifies a finalize warning or violation, mirroring the
-// FINALIZE_ERROR_CODE enum in proto/rho/contracts/v1/tool.proto.
+// FINALIZE_ERROR_CODE enum in the host tool contract.
 type FinalizeErrorCode int
 
 const (
@@ -90,7 +90,7 @@ func (r FinalizeResult) Ok() bool {
 }
 
 // ToolMeta is the canonical identity envelope attached to tool-call events,
-// mirroring the ToolMeta message in proto/rho/contracts/v1/tool.proto.
+// mirroring the ToolMeta message in the host tool contract.
 // version is an additive-only bump: new additive fields do NOT change it.
 type ToolMeta struct {
 	Version   string        `json:"version"`
@@ -102,11 +102,11 @@ type ToolMeta struct {
 }
 
 // ToolNamespace is a CLOSED enum identifying the harness that owns a tool,
-// mirroring the ToolNamespace enum in proto/rho/contracts/v1/tool.proto. A new
+// mirroring the ToolNamespace enum in the host tool contract. A new
 // unknown namespace is a wire-breaking change that intentionally fails
 // ToolNamespaceFrom (forward-safety): a deploy that rolls the contract forward
 // before the consumer code cannot silently mis-route a tool it doesn't
-// understand. ToolNamespaceAcp is reserved for the forthcoming rho-acp repo.
+// understand. ToolNamespaceAcp is reserved for a forthcoming ACP harness.
 type ToolNamespace string
 
 const (
@@ -116,7 +116,7 @@ const (
 	ToolNamespaceCodex           ToolNamespace = "codex"    // codex harness
 	ToolNamespaceOpencode        ToolNamespace = "opencode" // opencode harness
 	ToolNamespaceMcp             ToolNamespace = "mcp"      // MCP servers (falcon)
-	ToolNamespaceAcp             ToolNamespace = "acp"      // reserved: rho-acp
+	ToolNamespaceAcp             ToolNamespace = "acp"      // reserved: ACP harness
 )
 
 // ToolNamespaceFrom parses a namespace string into a ToolNamespace. The set is