Enable bugprone-empty-catch and eliminate empty catch handlers in core code

[Copilot]

This PR advances the clang-tidy-18 cleanup by re-enabling one previously disabled check (bugprone-empty-catch) and addressing its first-party findings with minimal behavioral impact. The scope is intentionally narrow: only the check enablement and directly affected catch blocks.

• Clang-tidy configuration

  • Re-enabled bugprone-empty-catch in .clang-tidy.

• Shared memory exception paths (src/storage/shared_memory.cpp)

  • Replaced empty catch (...) blocks in RegionExists with explicit return false;.
  • Added explicit return; in WaitForDetach catch blocks that intentionally swallow interprocess_exception.

• Parameter parsing error path (src/server/api/parameters_parser.cpp)

  • In bad_numeric_cast handling, return std::nullopt directly from the catch block to make the intent explicit and avoid an empty catch body.

try
{
    // ...
}
catch (...)
{
    return false; // explicit fallback instead of empty catch
}

Original prompt

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This section details on the original issue you should resolve

<issue_title>Fix clang-tidy warnings</issue_title>
<issue_description>We updated to clang-tidy 18 in https://github.com/Project-OSRM/osrm-backend/pull/6919/files and disabled some of newly introduced warnings. This issue is to track progress on fixing them:

• bugprone-chained-comparison
• bugprone-incorrect-enable-if
• bugprone-switch-missing-default-case
• bugprone-empty-catch
• bugprone-unused-return-value
• misc-include-cleaner
• performance-noexcept-swap
• performance-enum-size
• performance-avoid-endl
• readability-redundant-inline-specifier
• readability-avoid-nested-conditional-operator
• readability-avoid-return-with-void-value
• readability-redundant-casting

NOTE: some of them may be not actually very useful</issue_description>

<agent_instructions>create an individual pr for each of the disabled clang-tidy warnings, by enabling it and subsequently fixing the detected issues. Make sure the code is well formatted.</agent_instructions>

Comments on the Issue (you are @copilot in this section)

@SiarheiFedartsou https://github.com//pull/6934

• Fixes Fix clang-tidy warnings #6928

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