Stabilize self-analysis: fix false positives, bitfield handling, and warning hygiene (LLVM/SMT)

[SizzleUnrlsd]

Description

After struct layout/padding updates, self-analysis started reporting extra false positives (mainly uninitialized and duplicate-if) and compilation warnings (-Wreorder-init-list).

The goal is to fix behavior in the analyzer itself (no hardcoded suppression hacks), while keeping generic logic and backend compatibility (including SMT backends).

What was done

1. Refactored local control/data-flow paths to remove potential read of uninitialized local variable false positives without changing business semantics.
2. Improved UninitializedVarAnalysis to better handle constructor/bitfield read-modify-write (this) patterns and avoid non-actionable caller-side reports.
3. Refined DuplicateIfCondition branch reasoning (reachability/equivalent conditions) to reduce unreachable else-if false positives.
4. Fixed -Wreorder-init-list warnings in SMT stack components (SmtRefinement, SmtEncoding, Z3Backend) by matching designated-init order to declaration order.
5. Added false-positive repro tests and bitfield coverage tests to lock regressions.
6. Updated related project surfaces (docs/config/build/analyzer/app/cli) impacted by the fixes.

Architecture rationale

• Applied fixes in analysis engines instead of masking diagnostics.
• Kept rules generic and reusable (no single-case hardcoded patch).
• Preserved SMT backend compatibility, including Z3 when selected.

Acceptance criteria

• Target FP repros are covered by dedicated tests.
• -Wreorder-init-list warnings do not reappear on corrected units.
• No intended semantic regression on valid diagnostics.

Follow-up

• Track remaining cross-TU instability observed in full-run campaign (2 scenarios still inconsistent) in a separate issue.