Fix getInScopeFindings regression introduced by Pydantic refactor

[NoodlesNZ]

Fixes: #310
Regression introduced by: #320

What broke and why

PR #312 fixed issue #310 by adding ReportUtils.getInScopeFindings(), which filters threat findings to only those belonging to in-scope elements. The fix worked correctly against the pre-Pydantic codebase, where Finding.target held an Element object reference.

The Pydantic refactor (PR #320) changed Finding.target to a str (the element's name). This silently broke getInScopeFindings, the inner loop was now doing:

  getattr("Web Server", "inScope", False)  # always False

The result: getInScopeFindings returned [] for every element, including in-scope ones. All threat findings were hidden from advanced_template.md and reveal.md reports.

The out-of-scope case appeared to still work (returning []) but only because of the early-return guard at the top of the function, not because the inner loop was correct.

The fix
One-line change in report_util.py: use finding.element (the Element reference, set by Finding.init) instead of finding.target (the name string).

Note on root cause
The original state-bleed described in #310 (findings from one element appearing on another) was caused by a shared class-level list in the old descriptor system. That root cause was independently fixed by the Pydantic refactor, which uses default_factory=list to give each element instance its own findings list. The fix in this PR restores the template-level filtering that was broken as a side effect.

Tests

Seven new tests added to tests/test_report_util.py, covering:

• Non-element input returns []
• Out-of-scope element returns []
• In-scope element with one finding returns it
• In-scope element with multiple findings returns all of them
• In-scope element with no findings returns []
• Findings on one element do not appear on a different element (regression guard for Threats seem to "come through" to inScope = False assets #310)
• Out-of-scope element is unaffected by findings on a preceding in-scope element