fix(providers): bulk-add API keys no longer overwrite existing keys

Bulk-add named auto-generated keys by paste-line index, blind to existing
connection names. The backend upserts apikey connections by exact name
(connectionsRepo), so a colliding generated name silently replaced an
existing key instead of inserting a new one.

Add a collision-aware planner (src/shared/utils/bulkAdd.js) that gap-fills
the smallest free "<base> <n>" against both existing connection names and
names assigned earlier in the same batch, so a generated name is never
reused and the backend always inserts. Applies to auto-named lines, custom
name|apiKey lines, and Cloudflare name|apiKey|accountId lines.

Wire the planner into AddApiKeyModal and pass existing connection names
from the provider detail page. Add unit tests covering gap-fill, custom
names, Cloudflare 3-part format, and robustness.

src/shared/utils/bulkAdd.js

@@ -0,0 +1,94 @@
+// Bulk-add API-key planner.
+//
+// Background: the backend upserts apikey connections BY NAME
+// (src/lib/db/repos/connectionsRepo.js ~L144: existing = all.find(c =>
+// c.authType === "apikey" && c.name === data.name)). A colliding name
+// overwrites an existing key instead of inserting a new one. Bulk-add used to
+// derive "<base> <lineIndex>" from the paste position, blind to existing
+// names, so re-adding keys often silently replaced earlier ones.
+//
+// This planner gap-fills the smallest free "<base> <n>" against both existing
+// connection names and names already assigned earlier in the same batch, so a
+// generated name is never reused and the backend always inserts.
+//
+// ponytail: only numeric-suffix collision is handled. A user who manually
+// types an exact existing non-numbered custom name (no index) will still hit
+// the backend upsert — but bulk auto-naming always appends " <n>", so this
+// path is unreachable from the bulk modal. Upgrade path: a backend
+// "skip-if-exists" flag on POST /api/providers if single-add ever needs it.
+
+/**
+ * Parse one pipe-separated bulk line into { baseName, apiKey, providerSpecificData? }.
+ * @param {string} line
+ * @param {{isCloudflareAi?: boolean}} [opts]
+ * @returns {{baseName: string, apiKey: string, providerSpecificData?: object}|null}
+ */
+function parseLine(line, opts = {}) {
+  const { isCloudflareAi = false } = opts;
+  const parts = line.split("|");
+
+  if (isCloudflareAi && parts.length >= 3) {
+    // name|apiKey|accountId  (apiKey may itself contain pipes)
+    const baseName = parts[0].trim();
+    const apiKey = parts.slice(1, -1).join("|").trim();
+    const accountId = parts[parts.length - 1].trim();
+    return {
+      baseName: baseName || "Key",
+      apiKey,
+      providerSpecificData: { accountId },
+    };
+  }
+
+  if (parts.length >= 2) {
+    // name|apiKey  (apiKey may itself contain pipes)
+    const baseName = parts[0].trim();
+    const apiKey = parts.slice(1).join("|").trim();
+    return { baseName: baseName || "Key", apiKey };
+  }
+
+  // apiKey only — auto-named "Key N"
+  const apiKey = parts[0].trim();
+  return { baseName: "Key", apiKey };
+}
+
+/**
+ * Plan a bulk add: parse lines, assign collision-free "<base> <n>" names.
+ *
+ * @param {string[]} lines raw paste lines
+ * @param {string[]|null|undefined} existingNames connection names already saved
+ * @param {{isCloudflareAi?: boolean}} [opts]
+ * @returns {{name: string, apiKey: string, skipped: boolean, providerSpecificData?: object}[]}
+ */
+export function planBulkAdd(lines, existingNames, opts = {}) {
+  const { isCloudflareAi = false } = opts;
+
+  const safeExisting = Array.isArray(existingNames) ? existingNames : [];
+  const used = new Set(safeExisting.map((n) => (typeof n === "string" ? n.toLowerCase() : "")));
+
+  const out = [];
+  for (const raw of lines) {
+    const line = typeof raw === "string" ? raw.trim() : "";
+    if (!line) continue;
+
+    const parsed = parseLine(line, { isCloudflareAi });
+    if (!parsed || !parsed.apiKey) continue;
+
+    const base = parsed.baseName;
+
+    // Gap-fill from 1: smallest free "<base> <n>" not in `used`.
+    // O(batch * existing) — fine for bulk add (tens to low hundreds of keys).
+    let idx = 1;
+    let name;
+    for (;;) {
+      name = `${base} ${idx}`;
+      if (!used.has(name.toLowerCase())) break;
+      idx += 1;
+    }
+    used.add(name.toLowerCase());
+
+    const entry = { name, apiKey: parsed.apiKey, skipped: false };
+    if (parsed.providerSpecificData) entry.providerSpecificData = parsed.providerSpecificData;
+    out.push(entry);
+  }
+  return out;
+}