feat(market-profile): naked POC, single prints, profile shape, HVN/LVN, composite profile (B17) (#216)

## B17 Market Profile — five new indicators (493 → 498)

| Indicator | Output | Notes |
|-----------|--------|-------|
| `NakedPoc` | `f64` | most recent untouched point-of-control level |
| `SinglePrints` | `f64` | count of single-print price levels |
| `ProfileShape` | `f64` | b/P/D shape classification as a numeric code |
| `HighLowVolumeNodes` | struct `{hvn, lvn}` | highest/lowest volume nodes |
| `CompositeProfile` | struct `{poc, vah, val}` | multi-session composite volume profile |

### Wiring
- Core structs + full unit tests; all join the existing **Market Profile** family.
- Hand-written Python/Node/WASM bindings (f64 via candle helpers; struct via PyArray2 / `#[napi(object)]` / `Object`+`Reflect::set`).
- Fuzz drives in `indicator_update_candle.rs`; CANDLE_SCALAR + MULTI registry tests + reference tests.
- README counter + `docs/README.md` + `FAMILIES` assert bumped to 498.

### Verify (local, all green)
- `cargo test -p wickra-core --lib`: 4066 · `--doc`: 448
- clippy workspace: clean
- node: 568 · pytest: 938

CHANGELOG.md

@@ -6,6 +6,11 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+- **Composite Profile** — multi-session composite volume profile exposing POC, VAH and VAL (`CompositeProfile`).
+- **High/Low Volume Nodes** — highest- and lowest-volume price nodes in the profile (`HighLowVolumeNodes`).
+- **Profile Shape** — profile shape classification (b/P/D normal) as a numeric code (`ProfileShape`).
+- **Single Prints** — count of single-print (low-activity) price levels in the profile (`SinglePrints`).
+- **Naked POC** — most recent untouched (naked) point of control level (`NakedPoc`).
 
 ## [0.7.1] - 2026-06-08
 - **Open-Interest Momentum** — rate-of-change of open interest over a rolling window (`OpenInterestMomentum`).