release(0.2.1): bump to 0.2.1, skipping Windows ARM64 this cycle

The 0.2.0 release left wickra@npm stuck at 0.1.4 and never created a
GitHub Release entry because the brand-new `wickra-win32-arm64-msvc`
sub-package name was caught by npm's spam-detection filter on its first
publish attempt (same situation that affected `wickra-win32-x64-msvc`
through 0.1.4 until npm Support unblocked it). A support ticket is open;
until it is resolved, ship 0.2.1 for the five platforms whose
sub-packages are already on npm and re-add Windows ARM64 in a follow-up
release.

Changes for this cycle:
- bindings/node/package.json: remove "wickra-win32-arm64-msvc" from
  optionalDependencies and "aarch64-pc-windows-msvc" from
  napi.triples.additional.
- bindings/node/npm/win32-arm64-msvc/: removed (will be restored fresh
  once the npm name is unblocked).
- .github/workflows/release.yml: comment out the
  aarch64-pc-windows-msvc entry of the node-build matrix with a
  TODO/restore note.
- Bump every workspace and binding version to 0.2.1 (Cargo.toml,
  pyproject.toml, bindings/node/package.json, five npm/<target>
  templates, the wiki version table). Cargo.lock regenerated.
- CHANGELOG: new [0.2.1] block consolidating every fix that has landed
  on main since 0.2.0 (HV epsilon, examples CI step, fuzz cargo-fuzz
  install, MSRV 1.85 -> 1.86 / 1.77 -> 1.88, criterion 0.5 -> 0.8,
  tokio-tungstenite 0.24 -> 0.29, tick_aggregator gap-fill cap, every
  GitHub Action SHA-pin bump). Compare-link added.

The arm64 loader branch in bindings/node/index.js is left untouched: a
Windows ARM64 user installing 0.2.1 will get the standard
`Cannot find module 'wickra-win32-arm64-msvc'` error from the loader,
which is accurate. PyPI's win-arm64 wheel is unaffected.

Verified locally:
  cargo fmt/clippy/test --workspace --all-features -> 630 passed / 0 failed
  cargo build -p wickra-examples --bins -> clean
  cargo build -p wickra-node -> clean

docs/wiki/Quickstart-Node.md

@@ -10,12 +10,12 @@ slow JS reimplementation.
 npm install wickra
 ```
 
-> **Windows install (0.2.0+).** Earlier patch releases were blocked on
+> **Windows install (0.2.1+).** Earlier patch releases were blocked on
 > Windows x64 because the platform-specific sub-package
 > `wickra-win32-x64-msvc` was held back by npm's automated spam filter, so
 > `require('wickra')` threw `Error: Cannot find module
 > 'wickra-win32-x64-msvc'` after a successful `npm install`. npm Support
-> released the name on 2026-05-22; 0.2.0 is the first version in which
+> released the name on 2026-05-22; 0.2.1 is the first version in which
 > Windows x64 installs cleanly end-to-end (version numbers `0.1.1`–`0.1.4`
 > of that sub-package remain burned and cannot be republished — see the
 > npm registry page for `wickra-win32-x64-msvc`). Linux x64, Linux arm64
@@ -135,7 +135,7 @@ The complete TypeScript definitions live at
 | `batch(...)`              | Single-output: flat `Array<number>` with `NaN` warmup.<br>Multi-output: flat interleaved `Array<number>`. |
 | `reset()`                 | Returns to a freshly-constructed state.                                |
 | `isReady()`               | `true` once the first value has been emitted.                          |
-| `warmupPeriod()`          | Present on every indicator class (single- and multi-output, scalar- and candle-input) since `0.2.0`. |
+| `warmupPeriod()`          | Present on every indicator class (single- and multi-output, scalar- and candle-input) since `0.2.1`. |
 
 A complete reference run lives in `bindings/node/__tests__/smoke.test.js`: