docs: finish dropping the stripped-newline rule from the input docs

The first commit left the old rule standing in places: the gotchas list in
extending-codeman.md still said newlines were stripped and that
"echo A\necho B\r" ran `echo Aecho B`, and so did both READMEs and the
skill's big-input section. Those now describe the paste.

Newlines are only kept on the mux path, so the docs that describe the paste
say "with useMux": without it a multi-line body is not a plain prompt and is
written straight into the pane.

Cron keeps rejecting multi-line prompts, but its docs and the code comments
in cron-service.ts, schemas.ts and respawn-controller.ts gave a reason this
change removes (writeViaMux joining lines, a newline submitting in Ink). The
reason that remains is the submit check, which cannot recognise a
multi-line paste in the composer, and for cron's paste mode the newlines
reaching the CLI as keys.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

src/cron/cron-service.ts

@@ -97,7 +97,7 @@ const CRON_PSEUDO_FS_TREES: readonly string[] = ['/proc', '/sys', '/dev'];
 /** Sync blocklist for the create/update workingDir gate (no settings extras). */
 const CRON_WORKING_DIR_BLOCKED_TREES: readonly string[] = [...DEFAULT_BLOCKED_TREES, ...CRON_PSEUDO_FS_TREES];
 
-/** Prompt delivery is single-line only (writeViaMux/Ink constraint). */
+/** Prompt delivery is single-line only: the submit check cannot recognise a multi-line paste. */
 const HAS_NEWLINE = /[\r\n]/;
 
 /** The three session calls prompt delivery needs, so it can be tested without a PTY. */

src/respawn-controller.ts

@@ -2829,7 +2829,8 @@ export class RespawnController extends EventEmitter {
         let updatePrompt = this.config.updatePrompt;
 
         if (statusBlock?.recommendation) {
-          // Append RECOMMENDATION to the update prompt (single-line — writeViaMux breaks on newlines)
+          // Append RECOMMENDATION to the update prompt (single-line: the submit check cannot
+          // recognise a multi-line paste in the composer)
           const rec = statusBlock.recommendation.replace(/\n/g, ' ').substring(0, 200);
           updatePrompt = `${this.config.updatePrompt} (Claude's last recommendation: ${rec})`;
           this.logAction('ralph', `Using RECOMMENDATION: ${rec.substring(0, 50)}...`);

src/web/schemas.ts

@@ -1905,7 +1905,7 @@ export const ScheduledRunSchema = z.object({
 /** 'HH:MM' 24-hour time. */
 const hhmmSchema = z.string().regex(/^([01]?\d|2[0-3]):[0-5]\d$/, 'Time must be HH:MM (24-hour)');
 
-/** Prompt delivery is single-line only (writeViaMux/Ink constraint) — reject newlines outright. */
+/** Prompt delivery is single-line only (the submit check cannot see a multi-line paste) — reject newlines outright. */
 const noNewlines = (v: string) => !/[\r\n]/.test(v);
 
 /** Shared field shape for creating/updating a scheduled job. */