refactor(agentic): decompose queue frontend foundations and lowering

[hmljy2020]

Summary

• decompose the monolithic Queue frontend into the private _queue_compiler package: source/provenance helpers, AST normalization, immutable model definitions, static type analysis, ACIR text rendering, expression emission, QueueProgram -> raw ACIR lowering, parser state/context, module specialization, and ordered Queue/Memory/Table/Slot/endpoint statement handlers
• keep _queue_frontend.py as the compatibility and source-lowering facade
• explicitly re-export all 131 legacy top-level frontend definitions with canonical object identity; preserve existing private import paths during the staged [Agentic Circuit/Frontend] 渐进拆分 _queue_frontend.py 的解析、分析与 lowering 职责 #147 migration
• preserve ACPy, raw ACIR, direct GFSim C++, diagnostics, source locations, specialization metadata, SSA order, and public behavior
• reduce _queue_frontend.py from about 19,700 lines to under 200 lines without redesigning parsing or semantics

Issue #147 Progress

This PR completes the mechanical extraction through source/normalization, model/static types, expression/lowering, explicit parser state/context, resource statement handlers, and module orchestration.

Still intentionally deferred:

• separation of rule parsing from effect analysis
• removal of parser-time expression validation coupling
• replacement of inherited selection-alias shadowing
• final removal of temporary private facade re-exports after repository callers migrate

Lowering consumes the captured QueueProgram and its stored expression ASTs; it does not reparse Python source or recompute parser effects.

pyc6 Decision / Contract Impact

• Decision 0148 is preserved; no semantic change
• no dialect, verifier, pass, backend, scheduling, or runtime behavior changes
• diagnostic registry changes update source provenance only

Review Fixes

• restored the complete legacy facade compatibility inventory after review found dropped private imports
• moved semantic type rendering into dependency-free _queue_compiler/type_rendering.py
• restored package-wide enforcement that .mlir() is called only through _render_type
• removed dead parser aliases while retaining the intentional source_frame compatibility re-export

Validation

• required GitHub G0 checks passed on the original head; refreshed checks are required for the review fix commit
• frontend: 410 tests passed, 5 skipped
• contracts: 57 passed
• root unit suite: 147 passed
• import-order matrix: 21/21 passed
• facade/type-hygiene focused tests: 12/12 passed
• 217 representative base/head differential lowerings: zero mismatches
• repeated lowering: zero determinism mismatches
• import graph: acyclic
• contract checker, diagnostic catalog, compileall, changed-file pre-commit, API hygiene, and diff check passed

The one native JIT frontend case also passed when pointed at the current acir-opt and acir-queue-cxxgen tools. Release-only AC G1/G2, Verilator, and release closure remain outside this Python-only refactor PR.

Risk / Compatibility

• user-visible impact: none
• the facade compatibility manifest is intentionally temporary and test-locked
• moved objects report their canonical _queue_compiler implementation modules through __module__; wrapper copies are not created
• parser/effect-analysis redesign remains follow-up work under [Agentic Circuit/Frontend] 渐进拆分 _queue_frontend.py 的解析、分析与 lowering 职责 #147

Related Issues

• Advances [Agentic Circuit/Frontend] 渐进拆分 _queue_frontend.py 的解析、分析与 lowering 职责 #147; the issue remains open for the deferred effect-analysis and final compatibility-cleanup phases

[hmljy2020]

已推送 Queue parser 第一轮内部拆分，PR head 已从 48d981be fast-forward 到 fd08d0bd。

本轮新增三个可独立审阅和回退的提交：

• 0d292704 refactor(agentic): introduce queue parser state
• 78a90cd3 refactor(agentic): extract queue graph statement handlers
• fd08d0bd refactor(agentic): extract queue terminal statement handlers

完成内容：

• 增加私有 _ParserEnvironment 和 _ParserState，统一保存只读类型、静态参数、rule 定义、binding、名称索引、source frame 和唯一的 statement order；
• 建立显式有序 HANDLED / UNHANDLED handler 协议，调用优先级、递归和 continue 仍由 parser 明确控制；
• 迁移 merge、reorder、depend、collection select、credit、selected/direct memory request 和已移除 Queue.memory 的诊断；
• 迁移 barrier、route、fork、expect、observe、sink 和 return；
• 更新 diagnostic registry 的实现源码位置；
• visit() 已缩减到 2,937 行；handler 不反向导入 parser/facade，parser 未重新依赖 _queue_frontend.py。

最终验证：

• frontend：406 passed，2 skipped；
• contracts：53 passed；
• pytest tests/unit -m unit：147 passed；
• frontend/compile 确定性检查：5 passed；
• diagnostic catalog、compileall、changed-file pre-commit、import/unused-import 检查和 git diff --check 均通过。

完整 CLI lane 仍报告本机环境/已有构建库存问题：48 passed、6 failed、2 errors、1 skipped。失败集中于 linux-aarch64 SDK planning 未支持、staged runtime fixture 仍含 LLVM header，以及本地 native extension 的 module inventory/order 与当前源码不一致；没有失败指向本轮 parser/handler 文件。

本轮保持纯结构重构，不改变 Python 语法、QueueProgram、诊断文本、ACIR 或 GFSim C++ 语义，也未触及 dialect/pass/verifier/backend，因此未扩大到 G1/G2/Verilator。

[zhoubot]

Re-reviewed at 7f8cd41. Independent code review: APPROVE; architectural status: CLEAR. The legacy facade compatibility blocker, package-wide type-rendering boundary, and dead extraction aliases are fixed. Frontend 410/410 (5 skipped), contracts 57/57, unit 147/147, import-order 21/21, differential lowering 217/217, and both required G0 checks pass.