fix(#2505): set USERPROFILE in kimi-variant test env + add issue refs on allow-test-rule exemptions (#2545)

The kimi-variant-disambiguation test set only HOME in the spawnSync env,
but os.homedir() on Windows resolves USERPROFILE — so the installer never
found the probe config files and the 'variant mismatch' warning never
fired. Every other installer test in the repo sets both HOME and
USERPROFILE (agent-skills, augment-upgrades, antigravity-upgrades, etc.);
this one was newly written for Phase 5 and missed the pattern.

Also: both new test files carried allow-test-rule exemptions without the
'see #NNN' issue reference required by ADR-456, failing lint-allow-test-rule-refs.

tests/kimi-variant-disambiguation.test.cjs

@@ -1,4 +1,4 @@
-// allow-test-rule: behavioral-subprocess-test — Phase 5 kimi-variant
+// allow-test-rule: behavioral-subprocess-test — see #2505 — Phase 5 kimi-variant
 // disambiguation is verified via install.js subprocess output capture, since
 // the disambiguateKimiVariant function is inline in bin/install.js (not
 // exported). The test sets a disposable HOME, creates the probe config files,
@@ -27,7 +27,7 @@ function runInstall(args, home) {
   // spawnSync captures stdout AND stderr separately regardless of exit code
   // (execFileSync drops stderr on success, which hid the console.error warnings).
   const r = spawnSync('node', [INSTALL_JS, ...args], {
-    env: { ...process.env, HOME: home, GSD_TEST_MODE: '1' },
+    env: { ...process.env, HOME: home, USERPROFILE: home, GSD_TEST_MODE: '1' },
     encoding: 'utf8',
     timeout: 15000,
   });

tests/resolve-dispatch-type.test.cjs

@@ -1,4 +1,4 @@
-// allow-test-rule: behavioral-query-coverage — this test exercises the
+// allow-test-rule: behavioral-query-coverage — see #2505 — this test exercises the
 // resolve-dispatch-type query end-to-end (subprocess) AND the pure
 // resolveDispatchType function (require), covering the runtime-aware dispatch
 // contract from epic #2505 Phase 4 (#2508). The query is the workflow-facing