chore: delete the committed root screenshot --full-page, ignore dash-prefixed root files

.changeset/root-screenshot-dash-flag-ignore.md

@@ -0,0 +1,24 @@
+---
+---
+
+chore: delete the committed root screenshot `--full-page`, and ignore dash-prefixed root files
+
+Release-nothing: removes a stray binary from the repository root and touches
+`.gitignore` / `AGENTS.md` only — no package code changes.
+
+The repository root carried a **tracked** 68KB PNG whose filename was literally
+`--full-page` (1280x577). A screenshot CLI flag landed in the output-filename
+slot and was committed alongside #3085, so every `git worktree add` since has
+materialised the file into a fresh tree.
+
+The existing safety net could not catch it. `.gitignore` anchors `/*.png` and
+friends at the root precisely for stray screenshots, but this file has no
+extension to match on — the flag *is* the name. `.gitignore` now also ignores
+`/--*`: root-anchored, and matching the accident by its **shape** rather than
+by its content type. Nothing legitimate lives at the repository root under a
+flag name, so a root entry starting with `--` is an argument-parsing mistake by
+construction. Nested paths are unaffected (`packages/**/--foo` still shows up).
+
+Footnote for whoever meets the next one: a leading-dash filename is parsed as an
+option by every CLI, so it needs `--` and an explicit path —
+`git rm -- './--full-page'`, `rm -- ./--full-page`.

.gitignore

@@ -69,6 +69,14 @@ playwright-report
 /*.webp
 /*.heapsnapshot
 /*.trace
+# The extension-less shape the patterns above cannot catch: a root entry whose
+# name starts with `--` is a CLI flag that got captured as an output filename
+# (`... --full-page` written as `... > --full-page`, or a misordered argument),
+# so it carries no extension to match on. Such a name is an argument-parsing
+# accident by construction — nothing legitimate lives at the repo root under a
+# flag name. See #3193, where a 68KB PNG literally named `--full-page` rode in
+# with #3085 and reached every new worktree.
+/--*
 
 # Vite timestamp files
 *.timestamp-*.mjs

AGENTS.md

@@ -145,7 +145,8 @@ export const SchemaRenderer = ({ schema }: { schema: UIComponent }) => {
 
 ### Housekeeping
 - 截图/trace 一律存 `/tmp/`,任务尾清理。禁止写入仓库根。
-- `.gitignore` 已锚定 `/*.png` 等防兜底,但仍要主动清。
+- `.gitignore` 已锚定 `/*.png` 等防兜底,并额外忽略根级 `/--*` —— 名字以 `--` 开头的根文件必然是把 CLI 参数当成了输出文件名(#3193:一张叫 `--full-page` 的 68KB 截图被提交进来,因为没有 `.png` 后缀,`/*.png` 兜不住)。兜底只是最后一道,仍要主动清。
+  - 删这类文件要用 `--` 断开参数解析:`rm -- ./--full-page`、`git rm -- './--full-page'`。
 - 任务结束:停**自己起的**后台服务(见下方"服务纪律";别按端口杀别人的)、清 `.playwright-mcp/`。
 - 改完代码提交时:功能改进(feature)需写 changeset(`pnpm changeset`);纯 bug 修复不需要。