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fix: sync global variable map descriptors to SondePlatform (#539)

* fix(bpf): move global constants to stack to work around prevail-rust#1

Prevail's Rust bindings don't correctly type map_val references from
.rodata sections (map_type 0), causing LDDW to produce ctx-typed
pointers instead of shared-typed. This makes any program using
static const data fail verification.

Workaround: use stack-local arrays instead of file-scope static const.
This produces stack-typed pointers which Prevail accepts.

Upstream issue: https://github.com/elazarg/prevail-rust/issues/1

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* fix: sync global variable map descriptors to SondePlatform

prevail-rust promotes .rodata, .data, and .bss ELF sections to
map descriptors (map_type 0) during ELF loading via
\dd_global_variable_maps()\, but these descriptors are only stored in
the ELF loader's internal state — they are never propagated through
\parse_maps_section\ to the platform. As a result,
\SondePlatform::get_map_descriptor()\ returned \None\ for global
variable map FDs, causing the verifier to type \LDDW\-loaded registers
as \ctx\ instead of \shared\, which produced spurious verification
failures on any program referencing \.rodata\ maps.

Fix:

- Add \sync_map_descriptors()\ to \SondePlatform\ that mirrors the full
  set of \EbpfMapDescriptor\s from \RawProgram.info.map_descriptors\
  after ELF loading. \get_map_descriptor()\ checks the mirror first,
  falling back to the inner \LinuxPlatform\.

- Register map_type 0 in \get_map_type()\ as an array map so that
  \LDDW\ references produce \shared\-typed value pointers.

- Use prefix matching for global data section names in
  \xtract_global_section_data()\ (\.rodata.str1.1\, \.data.rel.ro\,
  etc.) to capture all sections Prevail promotes.

- Update gateway-requirements.md (GW-0404 criteria 5-6, GW-0405
  criterion 6) and gateway-design.md (§8.2.1.1) with the workaround
  and prefix matching beh... (continued)

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