feat: branding consistency checker

Branding is duplicated across Cargo.toml, bundler.toml, deploy.ps1 and
src/lib.rs with nothing keeping them in sync, so a rename drifts silently:
the bundle builds under one name while deploy.ps1 looks for another.

check-branding.sh declares the canonical identity once and asserts every
copy matches, including that VST3_CLASS_ID is exactly 16 bytes. A STALE
list catches leftovers of the old name after a rename. Portable POSIX sh
so it works on Windows (Git Bash) and Linux alike; .gitattributes pins
*.sh to LF so core.autocrlf=true cannot break the shebang.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LU1NRL7fAaZTtFMTTPn2b1

.gitattributes

@@ -0,0 +1,4 @@
+# Shell scripts must keep LF endings. core.autocrlf=true on Windows would
+# otherwise check them out CRLF, which a strict POSIX sh (dash, CI containers)
+# rejects at the shebang.
+*.sh text eol=lf

check-branding.sh

@@ -0,0 +1,76 @@
+#!/bin/sh
+# check-branding.sh - verify the plugin's branding/identity strings agree everywhere.
+#
+# Plugin branding is duplicated across the build manifest, the bundler manifest,
+# the deploy script and the source. Nothing makes them agree, so a rename drifts
+# silently: the bundle builds under one name and the deploy script looks for
+# another. This asserts they match, and that the identity constants are legal.
+#
+# Usage: sh check-branding.sh          (exit 0 = consistent, 1 = drift found)
+#
+# ---------------------------------------------------------------------------
+# CANONICAL IDENTITY - the single source of truth. Edit these to rename, then
+# run this script; every failure it prints is a place still holding the old name.
+# ---------------------------------------------------------------------------
+
+PKG="codename_206"                    # Cargo package name == bundler.toml table key
+DISPLAY="Codename 206"                # bundle name -> "<DISPLAY>.vst3" / "<DISPLAY>.clap"
+PLUGIN_NAME="206 prototype"           # Plugin::NAME - what the DAW displays
+CLAP_ID="com.mikkeli.codename-206"    # CLAP_ID - stable plugin identity
+VST3_CLASS_ID="Codename206Maxi!"      # VST3_CLASS_ID - stable identity, MUST be 16 bytes
+
+# Spellings that must no longer appear anywhere in tracked files. Populate this
+# with the OLD names after a rename to catch leftovers; keep empty otherwise.
+# Space-separated; use a form with no spaces, or quote carefully.
+STALE=""
+
+set -u
+cd "$(dirname "$0")" || exit 1
+
+pass=0; fail=0
+ok()   { pass=$((pass+1)); printf '  ok    %s\n' "$1"; }
+bad()  { fail=$((fail+1)); printf '  FAIL  %s\n' "$1"; [ $# -gt 1 ] && printf '        %s\n' "$2"; return 0; }
+
+# has FILE PATTERN -> fixed-string search
+has() { grep -qF "$2" "$1" 2>/dev/null; }
+
+check() { # check LABEL FILE LITERAL
+  if [ ! -f "$2" ]; then bad "$1" "missing file: $2"; return; fi
+  if has "$2" "$3"; then ok "$1"; else bad "$1" "$2 does not contain: $3"; fi
+}
+
+printf 'branding check (canonical: %s / "%s")\n\n' "$PKG" "$DISPLAY"
+
+printf 'build manifests\n'
+check "Cargo.toml package name"   Cargo.toml   "name = \"$PKG\""
+check "bundler.toml table key"    bundler.toml "[$PKG]"
+check "bundler.toml display name" bundler.toml "name = \"$DISPLAY\""
+
+printf '\nsource identity (src/lib.rs)\n'
+check "Plugin::NAME"    src/lib.rs "const NAME: &'static str = \"$PLUGIN_NAME\""
+check "CLAP_ID"         src/lib.rs "const CLAP_ID: &'static str = \"$CLAP_ID\""
+check "VST3_CLASS_ID"   src/lib.rs "const VST3_CLASS_ID: [u8; 16] = *b\"$VST3_CLASS_ID\""
+
+# VST3 class IDs are a fixed 16-byte array. A shorter or longer literal is a
+# compile error, but it is far clearer to say so here than to read rustc on it.
+n=$(printf '%s' "$VST3_CLASS_ID" | wc -c | tr -d ' ')
+if [ "$n" -eq 16 ]; then ok "VST3_CLASS_ID is 16 bytes"
+else bad "VST3_CLASS_ID is 16 bytes" "got $n bytes: \"$VST3_CLASS_ID\""; fi
+
+printf '\ndeploy script\n'
+check "deploy.ps1 default package" deploy.ps1 "\$Package = \"$PKG\""
+check "deploy.ps1 VST3 bundle"     deploy.ps1 "\$vst3Name = \"$DISPLAY.vst3\""
+check "deploy.ps1 CLAP bundle"     deploy.ps1 "\$clapName = \"$DISPLAY.clap\""
+
+if [ -n "$STALE" ]; then
+  printf '\nstale spellings\n'
+  for s in $STALE; do
+    hits=$(git ls-files 2>/dev/null | while read -r f; do
+             [ -f "$f" ] && grep -lF "$s" "$f" 2>/dev/null; done)
+    if [ -z "$hits" ]; then ok "no occurrences of \"$s\""
+    else bad "no occurrences of \"$s\"" "still present in: $(echo "$hits" | tr '\n' ' ')"; fi
+  done
+fi
+
+printf '\n%d passed, %d failed\n' "$pass" "$fail"
+[ "$fail" -eq 0 ] || exit 1