chore: removed old plan document

REFACTOR.md

@@ -1,91 +0,0 @@
-# Refactoring review
-
-This is the remaining refactoring backlog after PR #61. Completed work is
-intentionally omitted. Any implementation must preserve DS4 behavior,
-especially model execution, token processing, context accounting, and KV-cache
-handling.
-
-## Current assessment
-
-The codebase remains deliberate, concrete Rust. Database message invariants,
-runtime submission, checkpoint/source modeling, preference dispatch, and the
-pure A2UI evaluation and validation boundaries are now concentrated in clear
-locations.
-
-The remaining concentration is mostly in `App::update` and the Metal execution
-path. Neither justifies a broad framework: keep extracting only boundaries that
-already exist in the domain, and treat Metal changes as high-risk DS4 parity
-work.
-
-## Remaining work
-
-### 1. Continue reducing `App::update` at owned domain boundaries
-
-Priority: medium
-
-Preference messages now dispatch through `src/app/preferences.rs`, but
-`App::update` still spans roughly 890 lines and handles window lifecycle,
-projects, generation, A2UI, Git, model management, cache management, and native
-integration.
-
-Move another coherent message family only when its existing `src/app/*` module
-can own the complete handling flow. Keep the single public Iced update entry
-point. Avoid controller objects and generic dispatch infrastructure; with the
-current flat `Message` enum, extra pass-through matchers also weaken exhaustive
-matching and should earn that cost.
-
-### 2. Concentrate repeated Metal FFI invariants incrementally
-
-Priority: medium, high risk
-
-`src/engine/metal.rs` and `src/engine/metal/glm.rs` still contain many direct
-unsafe calls inside high-level execution logic. `src/engine/metal/gpu.rs`
-already proves that small wrappers can own repeated tensor, command, and
-lifecycle invariants, but coverage is incomplete.
-
-Add safe wrappers only for repeated, proven operations. Do not introduce a
-general GPU framework or reorganize execution merely to reduce unsafe-block
-count. Every change here requires DS4 parity coverage and the relevant real
-model/Metal fixtures.
-
-### 3. Replace argument-count suppressions only for existing records
-
-Priority: low
-
-Most remaining suppressions mirror explicit tensor/kernel operands or recursive
-A2UI traversal state and should stay. The clearest remaining candidate is
-metrics publication: `Metrics::ssd_stats` accepts nineteen fields that already
-travel together as execution statistics, and its call is duplicated in
-`src/engine.rs`.
-
-Reuse or introduce one concrete statistics record only if it removes that
-duplication without coupling metrics to the Metal executor. Do not create
-one-use parameter objects for `Generator::generate`, `Generator::compact`,
-Metal kernels, or A2UI rendering solely to satisfy Clippy.
-
-## Leave alone
-
-### Generated hotlist data
-
-`src/engine/metal/hotlist.rs` is mechanically generated. Deterministic embedded
-data with its import script is preferable to runtime machinery added only to
-reduce source size.
-
-### Preference-to-engine conversion
-
-The preference types and effective engine-setting types in `src/settings.rs`
-form a useful normalization boundary: optional user input is validated and
-converted into concrete DS4-compatible runtime values.
-
-### Concrete model descriptions
-
-The model `Shape` constants in `src/engine.rs` reuse common values with struct
-update syntax while keeping model differences explicit.
-
-## Suggested order
-
-1. Extract one more naturally owned `App::update` message family.
-2. Consolidate SSD metrics publication if a single concrete record keeps the
-   boundary simpler.
-3. Tighten repeated Metal FFI operations only alongside dedicated DS4 parity
-   tests and real fixture runs.