Cut non-essential prose from docs and comments, and require the same of every future change

README loses the competitor comparison, the personas and the repeated philosophy; the
five near-identical E2E command blocks become a table plus one command, and the file
map a clause per entry. AGENTS.md keeps every decision but drops the narrative around
them. todo.md's completed items collapse to their task line — git holds the rest.

Comments lose restatement, README duplication and history ("used to", "originally",
dated notes). AGENTS.md gains a Prose discipline section making this a standing pass on
every change rather than a one-off cleanup.

src/compose.test.ts now expects 6 documented E2E run commands, not 10, since the README
states the command once instead of per suite.

src/compose.test.ts

@@ -113,7 +113,7 @@ test("the E2E runner writes its artifacts as the invoking user, never as root",
   // filter would otherwise leave that command silently unguarded.
   const documented = [read("README.md"), ...composeFiles("e2e-tests/").map(read)]
     .join("\n").split("\n").filter((l) => /docker compose .*\brun\b.*\be2e\b/.test(l));
-  assert.equal(documented.length, 10, "5 compose headers + 5 README blocks");
+  assert.equal(documented.length, 6, "5 compose headers + 1 README block");
   for (const l of documented)
     assert.match(l, /--user "\$\(id -u\):\$\(id -g\)"/, `passes the uid: ${l.trim()}`);
   // An absent mount source is daemon-created as root, and then that uid can't write it at all.