Rename script/fetch-policy to script/commit-current-upstream-policy-docs

sneak, on the PR: the script does more than fetch, and short names are
not wanted. The make target, the test names, the variables and the
messages take the new name. Behaviour is unchanged.

Model: opus-5-5

prompts/REPO_POLICIES.md

@@ -110,7 +110,7 @@ style conventions are in separate documents:
     - `script/fmt-check`
     - `script/check`
     - `script/docker`
-    - `script/fetch-policy`
+    - `script/commit-current-upstream-policy-docs`
     - `script/update-policy`
 
     The scripts must be POSIX sh (`#!/bin/sh`, `set -eu`, no bashisms) so they
@@ -191,12 +191,13 @@ style conventions are in separate documents:
       `script/check`.
     - `script/install-precommit` installs the git pre-commit hook. The
       `make hooks` target shims to it.
-    - `script/fetch-policy` fetches the vendored policy files from the `prompts`
-      repo over HTTP and writes them into the repo it is given, or its own repo
-      with no argument.
-    - `script/update-policy` fetches the current `script/fetch-policy` from the
-      `prompts` repo, runs it on its own repo and commits the result. It does
-      not push. The `make update-policy` target shims to it.
+    - `script/commit-current-upstream-policy-docs` fetches the vendored policy
+      files from the `prompts` repo over HTTP and writes them into the repo it
+      is given, or its own repo with no argument.
+    - `script/update-policy` fetches the current
+      `script/commit-current-upstream-policy-docs` from the `prompts` repo, runs
+      it on its own repo and commits the result. It does not push. The
+      `make update-policy` target shims to it.
     - `script/projectname` (literally that filename) simply outputs the
       project's name.
 
@@ -937,19 +938,20 @@ style conventions are in separate documents:
   feature branch.
 
 - One command brings a repo up to standards: `make update-policy`. It runs
-  `script/update-policy`, which fetches the current `script/fetch-policy` from
-  the head of `main` in the `prompts` repo and runs it on the repo. It then
-  commits the files that changed and does not push, so a person reviews and
-  pushes the commit.
+  `script/update-policy`, which fetches the current
+  `script/commit-current-upstream-policy-docs` from the head of `main` in the
+  `prompts` repo and runs it on the repo. It then commits the files that changed
+  and does not push, so a person reviews and pushes the commit.
 
-    `script/fetch-policy` fetches each vendored file from `prompts` over HTTP
-    and writes it into the repo. It skips a language's files when git tracks no
-    source file of that language. A file the repo lacks is written whole. A
-    `prompts/NAME.md` goes to `docs/NAME.md`, unless the repo keeps it at
-    `NAME.md`. It also writes `script/fetch-policy` and `script/update-policy`
-    into the repo, so a repo updated once can update itself. The list of
-    vendored files is at the top of `script/fetch-policy`. The script replaces
-    each file and keeps only the repo's own entries:
+    `script/commit-current-upstream-policy-docs` fetches each vendored file from
+    `prompts` over HTTP and writes it into the repo. It skips a language's files
+    when git tracks no source file of that language. A file the repo lacks is
+    written whole. A `prompts/NAME.md` goes to `docs/NAME.md`, unless the repo
+    keeps it at `NAME.md`. It also writes
+    `script/commit-current-upstream-policy-docs` and `script/update-policy` into
+    the repo, so a repo updated once can update itself. The list of vendored
+    files is at the top of `script/commit-current-upstream-policy-docs`. The
+    script replaces each file and keeps only the repo's own entries:
     - in `.gitignore`, `.editorconfig` and `.dockerignore`: the lines below the
       comment that ends the canonical file
     - in a `.gitignore` or `.dockerignore` lacking that comment: every entry the
@@ -1182,7 +1184,8 @@ style conventions are in separate documents:
     - `Makefile`
     - `script/` entrypoints (`bootstrap`, `setup`, `projectname`, `test`,
       `lint`, `fmt`, `fmt-check`, `check`, `docker`, `cibuild`, `precommit`,
-      `install-precommit`, `fetch-policy`, `update-policy`)
+      `install-precommit`, `commit-current-upstream-policy-docs`,
+      `update-policy`)
     - `Dockerfile`, `.dockerignore`
     - `.gitea/workflows/check.yml`
     - Go: `go.mod`, `go.sum`, `.golangci.yml`