REPO_POLICIES: fix the second review's findings on the compaction (#158)

Fixes the seven findings of
#159 (comment), with
the wording each one gives.

- Go key points: "whatever files the mount holds".
- `.dockerignore`: "Such a `.dockerignore` is more dangerous than a
  short file with no secret patterns at all".
- Python: "pipenv checked the hashes of the lockfile's packages".
- Python: "In that step" leads only the two bullets about that step.
  The other four sit under "A Python repository's `script/bootstrap`:".
- Entrypoints: "Three more scripts have no required target:".
- Dockerfile: the two ways a stage installs what its image lacks are
  bulleted again, as on `next`.
- Version: the sentence ends at "stage-scoped", then "It has no
  default."
- `TODO.md`: the entry carries the new size, 1,066 lines and 7,812
  words.

Model: fable-5-1

TODO.md

@@ -21,6 +21,13 @@ fmt-check, and commit.
 
 # Completed Steps
 
+- 2026-11-06: Compacted `prompts/REPO_POLICIES.md` from 1,145 lines and 8,427
+  words to 1,066 lines and 7,812 words
+  (https://git.eeqj.de/sneak/prompts/issues/158). Every rule keeps its meaning.
+  The rules now sit under headings, the pinning rule first. Each rule that was
+  stated in several places is stated once. The Makefile copies of the Go and
+  Python test commands are gone, because the `Dockerfile` examples carry the
+  same commands. Both checklists name the `.golangci.yml` section.
 - 2026-11-06: The pinning rule in `prompts/REPO_POLICIES.md` now opens with its
   scope: what we download and install ourselves in scripts and Dockerfiles
   (https://git.eeqj.de/sneak/prompts/issues/154). Distribution packages are

prompts/EXISTING_REPO_CHECKLIST.md

@@ -163,7 +163,7 @@ with your task.
     - [ ] Go: `go.mod`, `go.sum`, `.golangci.yml` (fetch from
           `https://git.eeqj.de/sneak/prompts/raw/branch/main/.golangci.yml` and,
           in the same commit, set the lint phase digest to the one named in the
-          `.golangci.yml` paragraph of `REPO_POLICIES.md`)
+          `.golangci.yml` section of `REPO_POLICIES.md`)
     - [ ] JS: `package.json`, `yarn.lock`, `.yarnrc.yml`, `.yarn/releases/`,
           `.gitattributes`, `.prettierrc`, `.prettierignore` (fetch the last two
           from `https://git.eeqj.de/sneak/prompts/raw/branch/main/.prettierrc`

prompts/NEW_REPO_CHECKLIST.md

@@ -178,7 +178,7 @@ Template files can be fetched from:
     - [ ] Go: `go mod init sneak.berlin/go/<name>`, `.golangci.yml` (fetch from
           `https://git.eeqj.de/sneak/prompts/raw/branch/main/.golangci.yml` and,
           in the same commit, set the lint phase digest to the one named in the
-          `.golangci.yml` paragraph of `REPO_POLICIES.md`)
+          `.golangci.yml` section of `REPO_POLICIES.md`)
     - [ ] JS, or any repository that runs prettier through yarn: make the first
           `yarn.lock` with the steps below. `script/bootstrap` installs no yarn
           until `yarn.lock` exists, so run them with any distribution's node and