[compiler] Remove tryRecord, add catch-all error handling, fix remaining throws

[josephsavona]

Remove tryRecord() from the compilation pipeline now that all passes record
errors directly via env.recordError() / env.recordErrors(). A single
catch-all try/catch in Program.ts provides the safety net for any pass that
incorrectly throws instead of recording.

Key changes:

• Remove all ~64 env.tryRecord() wrappers in Pipeline.ts
• Delete tryRecord() method from Environment.ts
• Add CompileUnexpectedThrow logger event so thrown errors are detectable
• Log CompileUnexpectedThrow in Program.ts catch-all for non-invariant throws
• Fail snap tests on CompileUnexpectedThrow to surface pass bugs in dev
• Convert throwTodo/throwDiagnostic calls in HIRBuilder (fbt, this),
  CodegenReactiveFunction (for-in/for-of), and BuildReactiveFunction to
  record errors or use invariants as appropriate
• Remove try/catch from BuildHIR's lower() since inner throws are now recorded
• CollectOptionalChainDependencies: return null instead of throwing on
  unsupported optional chain patterns (graceful optimization skip)

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• [compiler] Update docs with fault tolerance summary, remove planning doc #35888
• [compiler] Fix Pipeline.ts early-exit, formatting, and style issues #35884
• [compiler] Rename mismatched variable names after type changes #35883
• [compiler] Remove local CompilerError accumulators, emit directly to env.recordError() #35882
• -> [compiler] Remove tryRecord, add catch-all error handling, fix remaining throws #35881