fix(browser): support configurable CDP auto-port range start (#31352)

* config(browser): add cdpPortRangeStart type

* config(schema): validate browser.cdpPortRangeStart

* config(labels): add browser.cdpPortRangeStart label

* config(help): document browser.cdpPortRangeStart

* browser(config): resolve custom cdp port range start

* browser(profiles): allocate ports from resolved CDP range

* test(browser): cover cdpPortRangeStart config behavior

* test(browser): cover cdpPortRangeStart profile allocation

* test(browser): include CDP range fields in remote tab harness

* test(browser): include CDP range fields in ensure-tab harness

* test(browser): include CDP range fields in bridge auth config

* build(browser): add resolved CDP range metadata

* fix(browser): fallback CDP port allocation to derived range

* test(browser): cover missing resolved CDP range fallback

* fix(browser): remove duplicate resolved CDP range fields

* fix(agents): provide resolved CDP range in sandbox browser config

* chore(browser): format sandbox bridge resolved config

* chore(browser): reformat sandbox imports to satisfy oxfmt

src/browser/server-context.ensure-tab-available.prefers-last-target.test.ts

@@ -12,6 +12,8 @@ function makeBrowserState(): BrowserServerState {
     resolved: {
       enabled: true,
       controlPort: 18791,
+      cdpPortRangeStart: 18800,
+      cdpPortRangeEnd: 18899,
       cdpProtocol: "http",
       cdpHost: "127.0.0.1",
       cdpIsLoopback: true,