## Problem
The R package built **only** inside the dev/CI workspace. `src/Makevars` and `configure.win` hard-required `WICKRA_INCLUDE_DIR` / `WICKRA_LIB_DIR` pointing at a pre-built `libwickra` (`configure.win` literally `: "${WICKRA_LIB_DIR:?...}"`), and there was no Unix `configure`. So **r-universe** and any plain `install.packages` / `install_github` failed — R had no working end-user install path.
## Fix
Fetch the prebuilt `wickra-c-<triple>.tar.gz` release asset matching the package version at install time and bundle the library into the package (same outcome as the C# / Java bindings, which bundle per-platform native libs):
- **New POSIX `configure`** (the Unix hook R lacked): detect OS/arch → triple, download + `untar` via **base R** (no curl/wget system dep), stage `wickra.h` + `libwickra.{so,dylib}` into `src/`, generate `src/Makevars` from `Makevars.in` with an rpath (`$ORIGIN` Linux, `@loader_path` + `install_name_tool` macOS) so the bundled lib resolves post-install.
- **`configure.win`**: drop the hard `WICKRA_LIB_DIR` requirement; download the Windows triple when unset, then keep the existing `wickra_abi.dll` rename + `objdump`/`dlltool` import-lib dance (sourcing the dll/header from the asset).
- **`install.libs.R`** also bundles `libwickra.dylib` (macOS); the `*.so`/`*.dll` globs already covered Linux/Windows.
- `WICKRA_INCLUDE_DIR`/`WICKRA_LIB_DIR` stay as an optional **dev override**.
- **CI (3 OS)** keeps building against the locally built C ABI (version-independent — avoids the chicken-egg of downloading the in-flight version) but **no longer exports `LD_LIBRARY_PATH`/`DYLD_LIBRARY_PATH`**, so it now verifies the bundled rpath — the real self-contained path users and r-universe get.
`Makevars` is now generated from `Makevars.in`; `SystemRequirements` + ignore/attributes files updated.
## Validation
- The Windows `objdump`/`dlltool` import-lib dance was smoke-tested locally against the real v0.7.9 asset (2412 `wickra_` exports → import lib built).
- Linux/macOS rpath bundling can't be tested on this Windows host → **the 3-OS `r` CI job is the gate** (now without the loader-path mask).
- Follow-up (separate, after release): set up `wickra-lib/wickra-lib.r-universe.dev` (`packages.json` → `bindings/r`).
Closes the R half of the self-contained-distribution gap (`todo-10`).
Adds a Java binding (`bindings/java`) over the C ABI hub — the fourth language stecker after C#, Go and R, reaching the hub through the Java Foreign Function & Memory API (Panama, `java.lang.foreign`, final in Java 22) rather than JNI or jextract.
## What's here
- **`bindings/java`** — a Maven module (`org.wickra:wickra`) exposing all 514 indicators as idiomatic `AutoCloseable` classes. The downcall handles (`internal/NativeMethods.java`), the per-indicator wrappers and the output records are generated from `bindings/c/include/wickra.h` (same eight-archetype taxonomy as the C#/Go/R generators: scalar/batch, multi-output, bars, profile, values-profile, array-input). The opaque handle is a `MemorySegment` freed by a registered `java.lang.ref.Cleaner` action; multi-output returns a `record` (`null` at warmup), bars a `record[]`, profiles a record with a trailing `double[]`. The hand-written `WickraNative` resolves the native library (a bundled per-platform copy, or a `target/release` fallback for local development) and validates it against a sentinel symbol. repr(C) struct offsets are computed in the generator so the FFM reads land on the exact bytes.
- **`examples/java`** — the full example suite mirroring C/C#/Go/R: streaming, backtest, multi_timeframe, parallel_assets (parallel streams), three strategies, and `FetchBtcusdt`/`LiveBinance`.
- **CI** — a `java` job builds the C ABI library, sets up JDK 22 (Temurin, with a CDN-flake retry), runs the archetype test suite and the seven offline examples on Linux, macOS and Windows.
- **Release** — a gated `java-publish` job (skipped until the `JAVA_PUBLISH_ENABLED` repository variable is set) stages the native libraries from the `wickra-c-<triple>.tar.gz` assets into the binding's resources and deploys to Maven Central with GPG signing. Independent of the GitHub-release job, like the NuGet job.
- **Docs** — Java added to the README languages table, project layout, building/testing and comparison table, CONTRIBUTING, ARCHITECTURE, the examples index, the issue/PR templates, the About-description template, and the other binding READMEs.
## Requirements
Java 22+ (the FFM API is final since Java 22). The binding requires `--enable-native-access=ALL-UNNAMED` at runtime; the test and example runners pass it automatically.
No Rust crate or `Cargo.toml` change — the Java binding is standalone and additive. The generated `*.java` are committed (like the node `index.js`/`index.d.ts`); the generator stays private.
Adds an R binding (`bindings/r`) over the C ABI hub — the third language stecker after C# and Go, reaching the hub through R's native `.Call` interface (not extendr).
## What's here
- **`bindings/r`** — an R package exposing all 514 indicators as constructors that return a `wickra_indicator` object with generic `update`/`batch`/`reset` methods. The C glue (`src/wickra.c`) and R wrappers (`R/indicators.R`) are generated from `bindings/c/include/wickra.h` (same archetype taxonomy as the C#/Go generators: scalar/batch, multi-output, bars, profile, profile-values, array-input). The opaque handle is an R external pointer freed by a registered finalizer; multi-output returns a named vector (`NA` at warmup), bars a matrix, profiles a list.
- **`examples/r`** — the full example suite mirroring C/C#/Go: streaming, backtest, multi_timeframe, parallel_assets (`mclapply`), three strategies, and `fetch_btcusdt`/`live_binance`.
- **CI** — an `r` job builds the C ABI library, installs the package, runs the `testthat` suite and the offline examples on Linux, macOS and Windows (`R CMD check` is clean: 0 warnings, 0 notes).
- **Docs** — R added to the README languages table, project layout, building/testing, CONTRIBUTING binding table + regenerate note, ARCHITECTURE, examples index, issue/PR templates, the About-description template, and the other binding READMEs.
## Linking / distribution
The package compiles a thin `.Call` glue layer against the prebuilt C ABI library (header via `WICKRA_INCLUDE_DIR`, library via `WICKRA_LIB_DIR`). On Windows the package's own `wickra.dll` would collide with the C ABI's `wickra.dll`, so `configure.win` stages a renamed copy (`wickra_abi.dll`) and builds an import library referencing it; `install.libs.R` bundles the DLL and `.onLoad` puts it on the load path. On Linux/macOS the rpath locates the shared library. No `release.yml` change — R is distributed via r-universe / source install (gated).
No Rust crate or `Cargo.toml` change — the R package is standalone and additive.
