Replace tmdb-* URL routing with resolveTitle/resolvePerson server actions

- Add `resolveTitle` and `resolvePerson` server actions that import
  from TMDB and return the internal DB id
- Remove `tmdb-{id}-{type}` URL pattern and server-side redirect logic
  from TitleDetailPage and PersonDetailPage
- Rename `importTitle` → `getOrFetchTitleByTmdbId`; add `getOrFetchTitle`
  combining fetch + children lookup
- Update HeroBanner, TitleCard, and CommandPalette to call resolve
  actions client-side before pushing to router
- Batch availability offer inserts into a single transaction

lib/actions/people.ts

@@ -0,0 +1,10 @@
+"use server";
+
+import { requireSession } from "@/lib/auth/session";
+import { getOrFetchPersonByTmdbId } from "@/lib/services/person";
+
+export async function resolvePerson(tmdbId: number): Promise<string | null> {
+  await requireSession();
+  const person = await getOrFetchPersonByTmdbId(tmdbId);
+  return person?.id ?? null;
+}

lib/actions/titles.ts

@@ -5,6 +5,7 @@ import { z } from "zod";
 import { requireSession } from "@/lib/auth/session";
 import { db } from "@/lib/db/client";
 import { episodes } from "@/lib/db/schema";
+import { getOrFetchTitleByTmdbId } from "@/lib/services/metadata";
 import {
   logEpisodeWatch,
   logEpisodeWatchBatch,
@@ -22,6 +23,15 @@ async function getSessionUserId() {
   return session.user.id;
 }
 
+export async function resolveTitle(
+  tmdbId: number,
+  type: "movie" | "tv",
+): Promise<string | null> {
+  await requireSession();
+  const title = await getOrFetchTitleByTmdbId(tmdbId, type);
+  return title?.id ?? null;
+}
+
 export async function updateTitleStatus(
   titleId: string,
   status: "in_progress" | null,

lib/actions/watchlist.ts

@@ -11,7 +11,7 @@ import {
   type HistoryBucket,
   type TimePeriod,
 } from "@/lib/services/discovery";
-import { importTitle } from "@/lib/services/metadata";
+import { getOrFetchTitleByTmdbId } from "@/lib/services/metadata";
 import {
   getEpisodeProgressByTmdbIds,
   getUserStatusesByTmdbIds,
@@ -41,7 +41,7 @@ export async function quickAddToWatchlist(
   const session = await requireSession();
   const userId = session.user.id;
 
-  const title = await importTitle(tmdbId, type);
+  const title = await getOrFetchTitleByTmdbId(tmdbId, type);
   if (!title) throw new Error("Failed to import title");
 
   const existing = db