chore(generator): retire ApiStyle::Std

The Std surface — std-typed signatures over a QVariant + LogosAPIClient
body — no longer had a caller. `interface: "universal"` modules moved to
`lp` (std types over the Qt-free logos-protocol C ABI), and nothing else
ever selected it, so every Std branch was dead weight sitting in front of
the two live ones.

`--api-style=std` is now rejected with a message naming the retirement
rather than aliased to `qt`. A stale caller that still passes it wants
std signatures; handing it the Qt surface would fail later, further from
the cause.

The collapse is deliberate about the branches where Std was tested BEFORE
Qt, since a naive "delete the block containing ApiStyle::Std" changes Qt
output:

- makeHeader's include block tested Std first, so its `else` is the Qt
  include list — the Qt includes are kept and promoted, not deleted.
- recordToWireExpr / recordFromWireExpr returned the Qt map form from a
  guarded `if` and the Std form from the function's trailing `return`.
  The guard is dropped and the Qt form promoted to the tail; deleting
  only the trailing return would have left a path falling off the end.
- The private-member `else if (!events.isEmpty())` arm reads as an event
  test but was Std-only; the Qt arm (m_eventReplica + m_eventSource)
  survives, so setEventSource/trigger still have their storage.
- `if (apiStyle == Qt || !events.isEmpty())` is a disjunction, not an
  Std branch: it unwraps to an unconditional emit, keeping
  ensureReplica()'s declaration next to its definition.
- `isRec || style == Std` loses only the right disjunct — dropping
  `isRec ||` would double-wrap record fields in QVariant::fromValue.

mapParamTypeStd / mapReturnTypeStd / isStdRefType stay: they are the
shared std type table that ApiStyle::Lp reaches through the non-Qt arm of
paramTypeFor / returnTypeFor / byRefFor and directly from lpPushExpr /
lpFromJsonExpr.

Verified by output equivalence rather than by the build succeeding: the
generator was run over 13 fixture cases (the full_api contract as both a
bound interface and a baked dep, three record-bearing contracts incl.
map-of-record fields, the chat module's production contract, and a
no-events contract) for both qt and lp, before and after. `diff -r` over
the 194 resulting files reports no differences, and the experimental
--lidl backends are byte-identical too. Test suite: 180/180, unchanged.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

cpp-generator/docs/project.md

@@ -92,7 +92,9 @@ The codegen exposes **one** wrapper class per module — `<Module>` — with sig
 | `--api-style` | Wrapper signatures |
 |---|---|
 | `qt` (default) | `QString` / `QStringList` / `QVariantList` / `QVariantMap` / `int` / `LogosResult` |
-| `std` | `std::string` / `std::vector<std::string>` / `LogosMap` / `LogosList` / `int64_t` / `StdLogosResult` |
+| `lp` | `std::string` / `std::vector<std::string>` / `LogosMap` / `LogosList` / `int64_t` / `StdLogosResult`, over the Qt-free logos-protocol C ABI |
+
+(A third value, `std` — std signatures over a `QVariant` / `LogosAPIClient` body — was retired; the generator now rejects `--api-style=std` instead of aliasing it.)
 
 Both styles emit:
 
@@ -113,15 +115,15 @@ Only the modules explicitly listed as dependencies are exposed. The runtime's `c
 
 `ApiStyle` enum + new helpers in `generator_lib`:
 
-- `enum class ApiStyle { Qt, Std }` — passed to every wrapper-emitting function.
-- File-local `mapParamTypeStd` / `mapReturnTypeStd` / `stdParamToQVariant` / `qVariantToStdReturn` — std-side type-mapping + Qt↔std conversion expressions. Hidden from `generator_lib.h` (not part of the public surface).
-- `makeHeader(moduleName, className, methods, apiStyle, events)` / `makeSource(moduleName, className, headerBaseName, methods, apiStyle, events)` — single entry points that branch on `apiStyle` internally to emit the right include block, signature shape, and conversion bridges. `events` is loaded from a `<name>.lidl` sidecar via `--events-from`; when non-empty, the wrapper also gets one typed `on<EventName>(callback)` adapter per declared event (callback arg types follow `apiStyle`). The std-style wrapper grows the necessary `ensureReplica()` plumbing on demand.
+- `enum class ApiStyle { Qt, Lp }` — passed to every wrapper-emitting function.
+- File-local `mapParamTypeStd` / `mapReturnTypeStd` — the std-side type-mapping table the `lp` surface exposes. Hidden from `generator_lib.h` (not part of the public surface).
+- `makeHeader(moduleName, className, methods, apiStyle, events)` / `makeSource(moduleName, className, headerBaseName, methods, apiStyle, events)` — single entry points that branch on `apiStyle` internally to emit the right include block, signature shape, and conversion bridges. `events` is loaded from a `<name>.lidl` sidecar via `--events-from`; when non-empty, the wrapper also gets one typed `on<EventName>(callback)` adapter per declared event (callback arg types follow `apiStyle`).
 
 Flag plumbing:
 
-1. `metadata.json#interface == "universal"` → `mkLogosModule.nix` adds `-DLOGOS_API_STYLE=std` to `extraCmakeFlags`. Anything else (`"legacy"`, `"provider"`, absent) leaves the default `qt`.
-2. `LogosModule.cmake` reads `${LOGOS_API_STYLE}` (default `qt`) and forwards `--api-style=${LOGOS_API_STYLE}` to the `logos-cpp-generator --general-only` invocation that writes the umbrella. Each module's Nix build emits **two** header derivations (`<name>.headers-qt` and `<name>.headers-std`) via `buildHeaders.nix` — one `logos-cpp-generator --api-style=…` run per style, at the dep's build time. A consumer's `buildPlugin.nix` picks `dep.headers-${apiStyle}` and copies its `include/` straight into the build sandbox; no codegen runs at consume time. Nix's laziness means only the variant a downstream actually depends on is realised.
-3. `legacy/main.cpp` parses `--api-style` once and threads the resulting `ApiStyle` through `generateFromPlugin`, `writeUmbrellaHeader{,FromDeps}`. No `_api_std.{h,cpp}` files are ever emitted; each module gets a single `<name>_api.h` + `<name>_api.cpp` pair regardless of style.
+1. `metadata.json#interface == "universal"` (or `"cdylib"`) → `mkLogosModule.nix` adds `-DLOGOS_API_STYLE=lp` to `extraCmakeFlags`. Anything else (`"legacy"`, `"provider"`, absent) leaves the default `qt`.
+2. `LogosModule.cmake` reads `${LOGOS_API_STYLE}` (default `qt`) and forwards `--api-style=${LOGOS_API_STYLE}` to the `logos-cpp-generator --general-only` invocation that writes the umbrella. Each module's Nix build emits **two** header derivations (`<name>.headers-qt` and `<name>.headers-lp`) via `buildHeaders.nix` — one `logos-cpp-generator --api-style=…` run per style, at the dep's build time. A consumer's `buildPlugin.nix` picks `dep.headers-${apiStyle}` and copies its `include/` straight into the build sandbox; no codegen runs at consume time. Nix's laziness means only the variant a downstream actually depends on is realised.
+3. `legacy/main.cpp` parses `--api-style` once (rejecting the retired `std`) and threads the resulting `ApiStyle` through `generateFromPlugin`, `writeUmbrellaHeader{,FromDeps}`. No per-style filenames are ever emitted; each module gets a single `<name>_api.h` + `<name>_api.cpp` pair regardless of style.
 
 ### Provider Generation (logos-qt-generator)
 
@@ -191,7 +193,7 @@ The `--events-from <path>` flag points the legacy `<plugin>.dylib --module-only`
 
 ```bash
 logos-cpp-generator /path/to/plugin.dylib \
-    --module-only --api-style std \
+    --module-only --api-style lp \
     --events-from /path/to/dep/share/logos/my_module.lidl \
     --output-dir ./generated
 ```

cpp-generator/docs/spec.md

@@ -321,7 +321,9 @@ Generated from LIDL (not from `--from-header`). Each module gets **one** `<Modul
 | `--api-style` | Wrapper signatures |
 |---|---|
 | `qt` (default) | QString / QStringList / QVariantList / QVariantMap / int / LogosResult |
-| `std` | std::string / std::vector<std::string> / LogosMap / LogosList / int64_t / StdLogosResult |
+| `lp` | std::string / std::vector<std::string> / LogosMap / LogosList / int64_t / StdLogosResult, over the Qt-free logos-protocol C ABI |
+
+(`std` — the same signatures over a `QVariant` / `LogosAPIClient` body — was retired; `--api-style=std` is now an error.)
 
 Both styles provide: