fix(bootstrap): gate local management controllers with the local feature state (#8221) - #8232

Fixes #8221.

Problem

With shenyu.local.enabled=false only the local dispatch filter is removed; the Local*Controller handlers stay registered as ordinary /shenyu controllers. HealthFilter dispatches configured path prefixes directly to DispatcherHandler without a method restriction, so broadening shenyu.health.paths to / exposes anonymous local plugin/selector/rule/metadata/app-auth writes. The starter's filter condition also used matchIfMissing=true, contradicting the false default of ShenyuConfig.Local.

Change

• All three local controllers and the LocalDispatcherFilter now share one explicit gate: shenyu.local.enabled=true (matchIfMissing=false).
• With the property absent or false, both the controllers and the filter are absent, so even a health prefix matching / finds no /shenyu handler and cannot reach a writer. With true, the existing key filter still runs before health dispatch and rejects missing/wrong keys.
• HealthFilter behavior and ordinary forwarding are unchanged.
• Compatibility: Omitting the property now disables local management entirely (previously the filter was implicitly registered and failed closed without a key). Deployments relying on implicit enablement must set shenyu.local.enabled=true and configure sha512Key; documented in the file-mode README, bootstrap defaults and root README. File mode continues to force it off.

Tests

• ShenyuConfigurationTest asserts the filter and all three controllers are absent when the property is omitted or false, and present when true.
• FileModeIntegrationTest starts a real Boot application with shenyu.health.paths=/ and asserts a POST to /shenyu/plugin/rule/saveOrUpdate returns 404 and leaves the rule cache unchanged; the controller and filter beans are absent.
• LocalManagementDispatchTest boots a real HTTP server with explicit enablement and a broad health prefix: a missing localKey is rejected with 403, while the correct key reaches the controller and updates the cache.

Verification

shenyu-web: 170/170
starter-gateway: 14/14
starter-sync-data-file: 72/72
wasm-base: 47/47
shenyu-common: 626 (4 skipped)
plugin-base: 334

Checkstyle clean on the touched modules. No request hot-path change: only startup bean registration is gated.