fix: use POST for file create in Gitea Contents API

Gitea's Contents API differs from GitHub's:
  POST /contents/{path} = create new file (no SHA)
  PUT  /contents/{path} = update existing file (SHA required)

store-github used PUT for createFile() because GitHub accepts PUT for
both — Gitea's PUT without SHA returns 422. Also updates the
update-fallback patch to bail to createFile() instead of falling through
to PUT-without-SHA when the file doesn't exist in the store.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

scripts/patch-store-github-gitea-methods.mjs

@@ -0,0 +1,96 @@
+/**
+ * Patch: fix store-github HTTP methods for Gitea's Contents API.
+ *
+ * GitHub API:  PUT /contents/{path}  = create-or-update (sha optional)
+ * Gitea API:   POST /contents/{path} = create (no sha)
+ *              PUT  /contents/{path} = update (sha required → 422 without it)
+ *
+ * Two changes:
+ * 1. createFile: use POST instead of PUT.
+ * 2. updateFile: when sha is undefined (file didn't exist), bail out to
+ *    createFile() instead of falling through to PUT-without-SHA which 422s.
+ *    Also restores plain `sha` in the PUT body (no longer need the spread
+ *    guard from patch-store-github-update-fallback since we bail early).
+ */
+
+import { readFile, writeFile, access } from "node:fs/promises";
+
+const TARGET = "node_modules/@indiekit/store-github/index.js";
+const MARKER = "// [patch] store-github-gitea-methods";
+
+// ── Change 1: createFile uses POST ──────────────────────────────────────────
+
+const OLD_CREATE_PUT = `      createResponse = await this.#client(filePath, "PUT", {`;
+const NEW_CREATE_POST = `      createResponse = await this.#client(filePath, "POST", { ${MARKER}`;
+
+// ── Change 2: updateFile bails to createFile when sha is undefined ───────────
+// Targets the block that starts after sha is resolved (by patch-store-github-update-fallback).
+// Replaces the spread-sha guard with an early-return to createFile.
+
+const OLD_UPDATE_SPREAD = `    const updateFilePath = newPath || filePath;
+
+    let updateResponse;
+    try {
+      debug(\`Try updating file \${filePath} in repo \${repo}, branch \${branch}\`);
+      updateResponse = await this.#client(updateFilePath, "PUT", {
+        branch,
+        content: Buffer.from(content).toString("base64"),
+        message,
+        ...(sha ? { sha } : {}), // [patch] store-github-update-fallback`;
+
+const NEW_UPDATE_SPREAD = `    if (!sha) { ${MARKER}
+      // File didn't exist — create it via POST instead of PUT-without-SHA (422 on Gitea)
+      return this.createFile(filePath, content, { message });
+    }
+
+    const updateFilePath = newPath || filePath;
+
+    let updateResponse;
+    try {
+      debug(\`Try updating file \${filePath} in repo \${repo}, branch \${branch}\`);
+      updateResponse = await this.#client(updateFilePath, "PUT", {
+        branch,
+        content: Buffer.from(content).toString("base64"),
+        message,
+        sha, ${MARKER}`;
+
+async function exists(p) {
+  try { await access(p); return true; } catch { return false; }
+}
+
+if (!(await exists(TARGET))) {
+  console.log(`[postinstall] store-github-gitea-methods: target not found, skipping`);
+  process.exit(0);
+}
+
+const source = await readFile(TARGET, "utf8");
+
+if (source.includes(MARKER)) {
+  console.log("[postinstall] store-github-gitea-methods: already patched");
+  process.exit(0);
+}
+
+let updated = source;
+let patched = 0;
+
+if (!updated.includes(OLD_CREATE_PUT)) {
+  console.warn("[postinstall] store-github-gitea-methods: createFile PUT snippet not found — skipping change 1");
+} else {
+  updated = updated.replace(OLD_CREATE_PUT, NEW_CREATE_POST);
+  patched++;
+}
+
+if (!updated.includes(OLD_UPDATE_SPREAD)) {
+  console.warn("[postinstall] store-github-gitea-methods: updateFile spread snippet not found — skipping change 2");
+} else {
+  updated = updated.replace(OLD_UPDATE_SPREAD, NEW_UPDATE_SPREAD);
+  patched++;
+}
+
+if (patched === 0) {
+  console.warn("[postinstall] store-github-gitea-methods: no changes applied");
+  process.exit(0);
+}
+
+await writeFile(TARGET, updated, "utf8");
+console.log(`[postinstall] store-github-gitea-methods: patched ${patched}/2 change(s) in ${TARGET}`);