refactor: unify peer kind to ChatType, rename dm to direct (#11881)

* fix: use .js extension for ESM imports of RoutePeerKind

The imports incorrectly used .ts extension which doesn't resolve
with moduleResolution: NodeNext. Changed to .js and added 'type'
import modifier.

* fix tsconfig

* refactor: unify peer kind to ChatType, rename dm to direct

- Replace RoutePeerKind with ChatType throughout codebase
- Change 'dm' literal values to 'direct' in routing/session keys
- Keep backward compat: normalizeChatType accepts 'dm' -> 'direct'
- Add ChatType export to plugin-sdk, deprecate RoutePeerKind
- Update session key parsing to accept both 'dm' and 'direct' markers
- Update all channel monitors and extensions to use ChatType

BREAKING CHANGE: Session keys now use 'direct' instead of 'dm'.
Existing 'dm' keys still work via backward compat layer.

* fix tests

* test: update session key expectations for dmdirect migration

- Fix test expectations to expect :direct: in generated output
- Add explicit backward compat test for normalizeChatType('dm')
- Keep input test data with :dm: keys to verify backward compat

* fix: accept legacy 'dm' in session key parsing for backward compat

getDmHistoryLimitFromSessionKey now accepts both :dm: and :direct:
to ensure old session keys continue to work correctly.

* test: add explicit backward compat tests for dmdirect migration

- session-key.test.ts: verify both :dm: and :direct: keys are valid
- getDmHistoryLimitFromSessionKey: verify both formats work

* feat: backward compat for resetByType.dm config key

* test: skip unix-path Nix tests on Windows

src/config/sessions/reset.test.ts

@@ -0,0 +1,72 @@
+import { describe, expect, it } from "vitest";
+import type { SessionConfig } from "../types.base.js";
+import { resolveSessionResetPolicy } from "./reset.js";
+
+describe("resolveSessionResetPolicy", () => {
+  describe("backward compatibility: resetByType.dm → direct", () => {
+    it("uses resetByType.direct when available", () => {
+      const sessionCfg = {
+        resetByType: {
+          direct: { mode: "idle" as const, idleMinutes: 30 },
+        },
+      } satisfies SessionConfig;
+
+      const policy = resolveSessionResetPolicy({
+        sessionCfg,
+        resetType: "direct",
+      });
+
+      expect(policy.mode).toBe("idle");
+      expect(policy.idleMinutes).toBe(30);
+    });
+
+    it("falls back to resetByType.dm (legacy) when direct is missing", () => {
+      // Simulating legacy config with "dm" key instead of "direct"
+      const sessionCfg = {
+        resetByType: {
+          dm: { mode: "idle" as const, idleMinutes: 45 },
+        },
+      } as unknown as SessionConfig;
+
+      const policy = resolveSessionResetPolicy({
+        sessionCfg,
+        resetType: "direct",
+      });
+
+      expect(policy.mode).toBe("idle");
+      expect(policy.idleMinutes).toBe(45);
+    });
+
+    it("prefers resetByType.direct over resetByType.dm when both present", () => {
+      const sessionCfg = {
+        resetByType: {
+          direct: { mode: "daily" as const },
+          dm: { mode: "idle" as const, idleMinutes: 99 },
+        },
+      } as unknown as SessionConfig;
+
+      const policy = resolveSessionResetPolicy({
+        sessionCfg,
+        resetType: "direct",
+      });
+
+      expect(policy.mode).toBe("daily");
+    });
+
+    it("does not use dm fallback for group/thread types", () => {
+      const sessionCfg = {
+        resetByType: {
+          dm: { mode: "idle" as const, idleMinutes: 45 },
+        },
+      } as unknown as SessionConfig;
+
+      const groupPolicy = resolveSessionResetPolicy({
+        sessionCfg,
+        resetType: "group",
+      });
+
+      // Should use default mode since group has no config and dm doesn't apply
+      expect(groupPolicy.mode).toBe("daily");
+    });
+  });
+});