fix(rp2040): honor bundled framework libraries and lib_deps

[zackees]

Problem

The RP2040/RP2350 build orchestrator does not discover or compile Arduino-Pico bundled framework libraries under framework/libraries, and it does not honor matching lib_deps declarations.

This blocks CYW43 WiFi on Raspberry Pi Pico W / Pico 2 W. A generated project with:

[env:rp2350w]
board = rpipico2w
framework = arduino
board_build.core = earlephilhower
lib_deps = WiFi

and a real #include <WiFi.h> fails under fbuild 2.5.7:

src/sketch/AutoResearchNet.cpp:898:10: fatal error: WiFi.h: No such file or directory

The same staged project metadata resolves framework-arduinopico/libraries/WiFi/src under PlatformIO. fbuild's installed Arduino-Pico package also contains libraries/WiFi, but the RP orchestrator only adds core, variant, manifest, SDK, and project include roots. In contrast, the Teensy and STM32 orchestrators call the shared framework-library selector and pass declared lib_deps.

Reproduction

Consumer: FastLED/FastLED issue #3832, staged rp2350w AutoResearch build with lib_deps = WiFi and the Arduino-Pico 4.5.3 framework override.

bash compile rp2350w --examples AutoResearch

Acceptance criteria

• RP2040/RP2350 discovers bundled Arduino-Pico libraries.
• Active include scanning and explicit lib_deps both select libraries through the shared LDF-style resolver.
• Selected framework sources are compiled and their include roots are available.
• A regression test proves declared WiFi selection on the RP orchestrator path.
• The FastLED RP2350W AutoResearch firmware compiles with the real CYW43/WiFi branch enabled.