process: switch WhatsNew.md and Notify text to English

Reversal of the language decision from 6d94fa5. Texts that get
committed to the repo permanently should follow the same English-
only rule as everything else; the Notify push stays 1:1 with the
WhatsNew entry, so both are English now.

The "only file intentionally not in English" carve-out in CLAUDE.md
is removed.

CLAUDE.md

@@ -194,9 +194,9 @@ is two-step and the two outputs share one text:
 The text must be written for the **user-as-reader who did not
 watch me work**:
 
-- **Language: German.** This is a deliberate exception to the
-  English-only project rule, because WhatsNew is user-facing
-  communication, the same role German plays in our live chat.
+- **Language: English.** Same as the rest of the repo; both
+  WhatsNew.md and the Notify push are permanent enough to be
+  treated as project content.
 - **No technical internals.** Don't name crates, function
   identifiers, type names, agent names, or iteration codes
   (`ct.1.7`, `18a`, etc.). Describe the *change in the project*
@@ -208,13 +208,13 @@ watch me work**:
   not an essay. If the work covered multiple unrelated things,
   bullet them.
 - **Tone: factual, not performative.** No celebration, no "I have
-  successfully…". Just "X geht jetzt, Y ist behoben, Z ist neu".
+  successfully…". Just "X works now, Y is fixed, Z is new".
 
 **Bounce-backs** (asking the user for a design judgement or
 checkpoint) are *not* done-state and do **not** produce a
 WhatsNew entry — they stay as Notify-only.
 
-Format of a WhatsNew entry: a `## YYYY-MM-DD — <kurze Überschrift>`
+Format of a WhatsNew entry: a `## YYYY-MM-DD — <short title>`
 heading followed by the message body. The body must match the
 Notify text verbatim.
 
@@ -270,12 +270,11 @@ Existing entries are not retroactively renamed.
   by `skills/implement`.
 
 - **`docs/WhatsNew.md`** (since 2026-05-11): the user-facing
-  changelog, written in German for the user-as-reader who does
-  not watch the implementation. Entries are appended at done-state
+  changelog, written for the user-as-reader who does not watch
+  the implementation. Entries are appended at done-state
   notifications and mirror the Notify text verbatim. See the
   "Done-state notifications" subsection above for the editorial
-  rules. This is the only file in the repo that is intentionally
-  not in English.
+  rules (in particular: no internals, lead with the change).
 
 Together these answer three questions: "what is the language right
 now?" (DESIGN), "how did we get here?" (JOURNAL, specs, plans),