feat: add a branding consistency checker

Adapted from musiikki/codename-206, where the same script guards a single
plugin. It matters more here: renaming is the first thing anyone does with
a template, and identity is duplicated across Cargo.toml, bundler.toml,
src/lib.rs and the docs with nothing keeping them in agreement. A
half-finished rename builds a bundle under one name while the docs and
deploy script look for another.

Changes from the codename-206 original:

- Checks for files this repo does not ship (deploy.ps1) report as `skip`
  rather than FAIL, and start enforcing once the file appears.
- STALE ships pre-seeded with this template's own placeholders, and each
  entry is skipped while it is still part of a canonical value. That makes
  renaming self-checking: entries arm themselves as you change the value
  they belong to, with no bookkeeping. Substring rather than equality,
  because placeholders nest — "your-domain" lives inside the canonical
  CLAP_ID.
- Covers identity this template carries that codename-206's did not:
  VENDOR, EMAIL, the Cargo homepage feeding Plugin::URL, that the `env!`
  indirection is still in place, and the README's bundle command.
- Asserts CLAP_ID is reverse-DNS safe. A stray capital or space there is
  not a compile error, it is a silent identity change between machines.

Two placeholder spellings had to move to avoid false positives, since a
checker that cries wolf trains you to ignore it: bundler.toml's comment
contained the literal "Plugin Name", and the CLAP_ID TODO spelled the
placeholder a third way that matched neither the constant nor the STALE
list. The TODO now illustrates the form instead of repeating a placeholder.

.gitattributes pins *.sh to LF so core.autocrlf=true on Windows cannot
check the script out with a CRLF shebang that dash rejects.

Verified three ways: clean template passes, a partial rename names every
drifted file, and a complete rename passes and still compiles.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WHt4DykxXaQnyaJfyS8KCn

README.md

@@ -13,8 +13,33 @@ cd my-plugin
 
 # Edit: src/lib.rs, Cargo.toml, bundler.toml — replace placeholder values
 # See musiikki/codename-206 for a real-world example of how to fill these in
+
+# Then verify the rename landed everywhere
+sh check-branding.sh
 ```
 
+## Renaming
+
+Branding is duplicated across `Cargo.toml`, `bundler.toml`, `src/lib.rs` and the docs,
+and nothing makes those agree — so a half-finished rename builds a bundle under one name
+while the docs and deploy script look for another.
+
+`check-branding.sh` declares the identity once at the top and asserts every copy matches:
+
+```bash
+sh check-branding.sh      # exit 0 = consistent, 1 = drift found
+```
+
+To rename: edit the canonical block at the top of the script, run it, and fix everything
+it reports. The placeholder spellings are pre-seeded into its `STALE` list, and each one
+arms itself as soon as you change the matching canonical value — so leftovers surface
+without you having to track them. It also asserts `VST3_CLASS_ID` is exactly 16 bytes and
+that `CLAP_ID` is reverse-DNS safe, both of which are otherwise a compile error or a
+silent identity change between machines.
+
+Checks for files the template doesn't ship (e.g. a `deploy.ps1`) report as `skip` and
+start enforcing once you add them.
+
 ## Build
 
 ```bash
@@ -74,6 +99,8 @@ bundler.toml        # Bundle name for `cargo xtask bundle`
 src/lib.rs          # Plugin skeleton — params, DSP, and egui editor, with one example gain param
 xtask/              # Bundler xtask (cargo xtask bundle)
 .cargo/config.toml  # xtask alias
+check-branding.sh   # Asserts the plugin's identity strings agree everywhere (see Renaming)
+.gitattributes      # Pins *.sh to LF so Windows checkouts keep a valid shebang
 ```
 
 ## License