fix: forward cycle context through acyclic helpers

[AGiorgetti]

Change

Fixes #25.

• Separate recursive source vertices from helpers that only forward cycle context. Acyclic object, struct, array, list, and dictionary bridges now compile and preserve the initiating method and complete path.
• Keep mixed declared/helper recursive components tracked; acyclic side bridges only forward context. Recursive roots and helpers release references in finally.
• Add 20 executable generator cases, a normal Basic sample, and matching clean-package, framework/language, trimming, and Native AOT consumer coverage. Synchronize usage, changelog, and control documents. No public API or specification semantics change.

Verification

• Tests-first: the completed 19-case matrix on unchanged develop produced 17 failures and two passing controls, zero skips. The twentieth mixed-component regression then failed the first candidate's over-tracking assertion before correction. Separate direct-root cleanup and normal-sample CS0103 failures are recorded.
• Final local generator suite: 696 passed, including all 20 new cases, zero failures/skips. Runtime 5/5, integration 1/1, and all three source sample smoke runs pass.
• Release solution build: zero warnings/errors. Actual netstandard2.0 package-generated source was inspected: one tracker, context-only Envelope/collection helpers, Node Enter/finally/Exit, and the full Envelope.Nodes.Next path.
• Available packaging suite: 220 passed, two infrastructure failures, zero skips. All 12 netstandard2.0/net8.0/net9.0/net10.0 and C# 9/14/latest combinations pass the new bridge fixture, along with clean-package samples, API/package checks, usage validation, and benchmark smoke.
• Local trimming and Native AOT fail at ILLink ComputeManagedAssemblies task-host creation (MSB4216 / Unix-domain SocketException 13). PowerShell and clang are absent; 49 PowerShell-dependent cases were not run locally. No local trimming/AOT success is claimed.
• Independent read-only review found no code or coverage blocker. CRLF-aware diff validation passes. No assertion, prerequisite, dependency, or warning was weakened.
• Remote tree a3ca19742d85e13b450ea2f60e054afe6e53f4ba matches the tested/staged local tree. Ordinary exact-head PR CI passed for 807644f. Windows and Linux each passed 973 tests (696 generator, 271 packaging, five runtime, one integration), zero failures/skips. All six Roslyn 4.8.0/4.14.0/5.9.0 OS jobs passed 696 tests each, zero failures/skips. Full packaging covers the PowerShell, trimming, and Native AOT checks unavailable locally. Both solution builds have zero warnings/errors. Release pack/artifact-verification/publication jobs were skipped as expected for this ordinary PR.

Submitted as a draft for human review; the maintainer merged it into develop at 38e313e on 2026-10-09 at 09:44:45 UTC. No agent merge, issue comments/claim writes, release, tag push, package publication, or workflow dispatch was performed. Other issues remain outside this fix.

Prepared with OpenAI Codex.