Two test files broken independently of eboot_core's build: test_slot_manager.c, test_boot_log.c #56

Found while verifying #55 (fixing eboot_core's build). These are two
separate, pre-existing, unrelated problems in the test suite — real, but each is
a larger undertaking than a quick fix, so filing them here rather than folding
them into that PR.

tests/unit/test_slot_manager.c — ~20 test functions called but never defined

PR #37 rewrote this file's fixture (old SLOT_A_ADDR/parse_result[]/ASSERT/RUN
style → new sim_flash/slot_states[]/PASS() style) to support new boot-attempt/
rollback tests. The patch was applied incompletely:

• Symbols the surviving old code still references (slot_index, SLOT_A_ADDR,
  SLOT_SIZE, erase_result) were deleted.
• New content was spliced into the middle of an existing function body rather than
  replacing it cleanly — eos_image_parse_header()'s body is truncated mid-statement,
  and the very next line starts a new function definition inside its still-open
  brace, which is illegal in C (error: function definition is not allowed here,
  repeated for every function after it).
• The new main() calls roughly twenty test functions (test_scan_one_valid_slot,
  test_slot_is_valid_empty, test_slot_erase, test_version_macro_encoding, …)
  that don't exist anywhere in the file — only their names appear in the call list.

Reproduce:

$ cc -fsyntax-only -x c -I include tests/unit/test_slot_manager.c
# 20 errors, starting with "use of undeclared identifier 'SLOT_B_ADDR'"

Fixing this properly means writing ~20 real test bodies against
eos_slot_manager.h's actual API — new test authorship, not a restoration.

tests/unit/test_boot_log.c — duplicate-symbol conflict with the real implementation

This file defines its own local mock of eos_boot_log_read() with a different
signature than the real one in core/boot_log.c ((entries, max_count) vs.
(index, out) — see #55 for why the header was corrected to match the real
implementation). But its CMake target also links the full eboot_core library,
which includes the real core/boot_log.c. That means even with a header fix,
this file redefines a symbol that's also present in the library it links against
— a duplicate-symbol conflict, not a simple signature mismatch. It needs a real
redesign (either drop the local mock and use the real implementation with a fake
HAL backend, or rename the mock), not a one-line fix.

Reproduce (after #55 is merged, since before that the header itself was also
wrong and masked this):

$ cmake --build build --target test_boot_log
# core/ed25519_verify.c:434: error: conflicting types for 'eos_boot_log_read'

Not investigated further

I didn't audit whether other test files have the same class of damage as
test_slot_manager.c — I found these two while trying to get eboot_core's own
tests running, not via a systematic sweep. Worth a broader look.