feat: add loom-config Debug flag, centralize debug diagnostics

[R-unic]

Summary

• TypeChecker.EmitDebugDiagnostics was a public static mutable bool that was never set anywhere in the codebase — debug diagnostics could literally never fire. Removed it.
• Added LoomConfig.Debug (debug = true in loom-config.toml).
• Centralized behind SemanticModel.EmitDebugDiagnostics, set once by Resolver from the compilation unit's config, and read by both Resolver and TypeChecker from the same shared SemanticModel instead of a scattered static.
• Wired Loom.CLI/Program.cs to pass debugDiagnostics: loomConfig.Debug instead of a hardcoded false, so the flag actually does something end-to-end.
• Resolver.DeclareSymbol used to emit up to 3 separate debug diagnostics per declared symbol ("Declared symbol: X", "X is global", "X is intrinsic"). Consolidated into one message per declaration, e.g. Declared 'Foo' (Interface) [global, ambient, intrinsic].
• Debug-severity diagnostics now render as a compact one-line message (debug [file @ line:col] message) instead of the full multi-line source-frame every other severity uses — appropriate for what's meant to be high-volume trace output. Error/Warn/Info rendering is unchanged.

Test plan

• dotnet build — succeeds, no warnings
• dotnet test — 1817/1817 pass
• Verified end-to-end: a real loom-config.toml with debug = true now prints compact debug diagnostics for every declared symbol and solved type; without the flag (or debug = false), output is unchanged from before ((none))

🤖 Generated with Claude Code

[github-actions]

Qodana for .NET

251 new problems were found

Inspection name	Severity	Problems
Auto-property accessor is never used (private accessibility)	🔶 Warning	6
Auto-property accessor is never used (non-private accessibility)	🔶 Warning	5
Non-accessed positional property (non-private accessibility)	🔶 Warning	2
Redundant name qualifier	🔶 Warning	1
Type member is never used (private accessibility)	🔶 Warning	1
Unused local variable	🔶 Warning	1
Type member is never used (non-private accessibility)	◽️ Notice	94
Use preferred style of 'new' expression when created type is not evident	◽️ Notice	83
Member can be made private (non-private accessibility)	◽️ Notice	20
Class is never instantiated (non-private accessibility)	◽️ Notice	4
Invert 'if' statement to reduce nesting	◽️ Notice	4
Some values of the enum are not processed inside 'switch' statement	◽️ Notice	4
Use preferred style for trailing comma before new line in multiline lists	◽️ Notice	3
Auto-property can be made get-only (non-private accessibility)	◽️ Notice	3
RoslynAnalyzers The member referenced by the MemberData attribute returns untyped data rows	◽️ Notice	3
RoslynAnalyzers Do not use Enumerable methods on indexable collections	◽️ Notice	2
Property can be made init-only (non-private accessibility)	◽️ Notice	2
Auto-property can be made get-only (private accessibility)	◽️ Notice	1
RoslynAnalyzers Use concrete types when possible for improved performance	◽️ Notice	1
RoslynAnalyzers Use char overload	◽️ Notice	1
'if-return' statement can be rewritten as 'return' statement	◽️ Notice	1
Foreach loop can be converted into LINQ-expression but another 'GetEnumerator' method will be used	◽️ Notice	1
Merge null/pattern checks into complex pattern	◽️ Notice	1
Redundant string interpolation	◽️ Notice	1
Replace with 'field' keyword	◽️ Notice	1
Some values of the enum are not processed inside 'switch' statement and are handled via default section	◽️ Notice	1
Tail recursive call can be replaced with loop	◽️ Notice	1
Type member is never accessed via base type (non-private accessibility)	◽️ Notice	1
Method return value is never used (non-private accessibility)	◽️ Notice	1
Literal length can be reduced by using verbatim string	◽️ Notice	1

☁️ View the detailed Qodana report

Detected 1 dependency

Third-party software list

This page lists the third-party software dependencies used in Loom

Dependency	Version	Licenses
Tomlyn	2.6.0	BSD-2-Clause

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