chore: sync v2/main to 2.2.0 and bump on v2/main before the milestone merge

v2/main has been at 2.0.0 since the v2.0.0 release while main and npm `latest`
are at 2.2.0. The bump was created on the milestone-merge branch, which is cut
from main, so it only ever existed downstream of v2/main and nothing carried it
back — `chore: 2.1.0` and `chore: 2.2.0` are both on main and neither is on
v2/main.

That is not cosmetic. A branch cut from a milestone-merge branch silently
carries the bump into an unrelated PR — #2009 arrived with a 2.0.0 -> 2.2.0 diff
on a container bugfix — and anything reading the version in development
(readInspectorVersion, --version, GET /api/config) reported a version two
releases old.

Move the bump to v2/main, before the milestone merge, so it flows into main with
the rest of the milestone's work and the branches never disagree. The release
tag is applied to the resulting main commit instead. The publish workflow needs
no change: its tag-vs-package.json assertion runs at the release commit on main,
which still carries the bump.

Deliberately not a back-merge of main into v2/main: main holds the whole pre-v2
v1 history (~230 commits v2/main lacks, retained through `chore: replace main's
tree with v2`), so merging would graft all of it into the develop branch's log
permanently to deliver a two-file change.

Also sets v2/main to 2.2.0 as a one-time catch-up. Nothing in the repo asserts a
specific version value, so this is a safe two-file change.

Closes #2010

Signed-off-by: cliffhall <cliff@futurescale.com>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@modelcontextprotocol/inspector",
-  "version": "2.0.0",
+  "version": "2.2.0",
   "description": "The Model Context Protocol Inspector",
   "keywords": [
     "MCP",