examples: move the bundled BTCUSDT datasets to a top-level examples/data/

The seven BTCUSDT OHLCV datasets used to live under
crates/wickra/examples/data/, which buried them inside a Rust crate even
though the Node backtest example and the upcoming Rust/Node/WASM example
restructure need to reach them too. Move them to the workspace-level
examples/data/ so every language's examples can resolve the same path.

The bench (crates/wickra/benches/indicators.rs), the example_data
integration test, fetch_btcusdt.rs and the Node backtest example all take
the new ../../examples/data/ path; Data-Layer.md, examples/README.md and
the CHANGELOG entry are updated to match. No data file content changes.

crates/wickra/benches/indicators.rs

@@ -6,14 +6,14 @@
 //! ```
 //!
 //! Each benchmark feeds real BTCUSDT 1-minute candles — read from the
-//! checked-in dataset `examples/data/btcusdt-1m.csv` — through both the
-//! streaming (`update` loop) and batch APIs of an indicator. Sizes cover
-//! small (1 000), medium (10 000), and large (50 000) workloads, taken as
-//! prefixes of that dataset.
+//! checked-in dataset at the workspace `examples/data/btcusdt-1m.csv` —
+//! through both the streaming (`update` loop) and batch APIs of an
+//! indicator. Sizes cover small (1 000), medium (10 000), and large
+//! (50 000) workloads, taken as prefixes of that dataset.
 //!
 //! Regenerate the dataset with:
 //! ```text
-//! cargo run -p wickra --example fetch_btcusdt
+//! cargo run -p wickra-examples --bin fetch_btcusdt
 //! ```
 
 use criterion::{black_box, criterion_group, criterion_main, BenchmarkId, Criterion, Throughput};
@@ -26,13 +26,17 @@ use wickra_data::csv::CandleReader;
 /// Workload sizes, in candles. Each is taken as a prefix of the dataset.
 const SIZES: &[usize] = &[1_000, 10_000, 50_000];
 
-/// Load the checked-in BTCUSDT 1-minute candle dataset.
+/// Load the checked-in BTCUSDT 1-minute candle dataset from the workspace
+/// `examples/data/` directory.
 fn load_candles() -> Vec<Candle> {
-    let path = concat!(env!("CARGO_MANIFEST_DIR"), "/examples/data/btcusdt-1m.csv");
+    let path = concat!(
+        env!("CARGO_MANIFEST_DIR"),
+        "/../../examples/data/btcusdt-1m.csv"
+    );
     let mut reader = CandleReader::open(path).unwrap_or_else(|e| {
         panic!(
             "could not open the benchmark dataset {path}: {e}\n\
-             generate it with `cargo run -p wickra --example fetch_btcusdt`"
+             generate it with `cargo run -p wickra-examples --bin fetch_btcusdt`"
         )
     });
     reader

crates/wickra/examples/data/btcusdt-1month.csv

@@ -1,106 +0,0 @@
-timestamp,open,high,low,close,volume
-1501545600000,4261.48,4745.42,3400,4724.89,10015.640272
-1504224000000,4689.89,4939.19,2817,4378.51,27634.18912
-1506816000000,4378.49,6498.01,4110,6463,41626.388463
-1509494400000,6463,11300.03,5325.01,9838.96,108487.978119
-1512086400000,9837,19798.68,9380,13716.36,408476.658399
-1514764800000,13715.65,17176.24,9035,10285.1,816675.564467
-1517443200000,10285.1,11786.01,6000.01,10326.76,1243940.85531
-1519862400000,10325.64,11710,6600.1,6923.91,1235326.31402
-1522540800000,6922,9759.82,6430,9246.01,1110964.015581
-1525132800000,9246.01,10020,7032.95,7485.01,914476.377885
-1527811200000,7485.01,7786.69,5750,6390.07,942249.765944
-1530403200000,6391.08,8491.77,6070,7730.93,1102510.436786
-1533081600000,7735.67,7750,5880,7011.21,1408159.816556
-1535760000000,7011.21,7410,6111,6626.57,1100653.423315
-1538352000000,6626.57,7680,6205,6371.93,629922.086219
-1541030400000,6369.52,6615.15,3652.66,4041.32,1210366.564567
-1543622400000,4041.27,4312.99,3156.26,3702.9,1591229.611862
-1546300800000,3701.23,4069.8,3349.92,3434.1,908244.14054
-1548979200000,3434.1,4198,3373.1,3813.69,861783.986727
-1551398400000,3814.26,4140,3670.69,4103.95,787190.48925
-1554076800000,4102.44,5600,4067,5320.81,1126961.315101
-1556668800000,5321.94,9074.26,5316.2,8555,1498410.025617
-1559347200000,8555,13970,7444.58,10854.1,1689489.647326
-1561939200000,10854.1,13147.08,9060,10080.53,1886176.065915
-1564617600000,10080.53,12330.7,9320,9587.47,1201961.576316
-1567296000000,9588.74,10905.87,7710,8289.34,1116856.475836
-1569888000000,8289.97,10370,7300,9140.85,1446763.024045
-1572566400000,9140.86,9513.68,6515,7541.89,1499118.774995
-1575158400000,7540.63,7750,6435,7195.23,1307033.020384
-1577836800000,7195.24,9578,6871.04,9352.89,1691323.137782
-1580515200000,9351.71,10500,8445,8523.61,1609726.154564
-1583020800000,8523.61,9188,3782.13,6410.44,3789768.913125
-1585699200000,6412.14,9460,6150.11,8620,2528373.691121
-1588291200000,8620,10067,8117,9448.27,2685340.078508
-1590969600000,9448.27,10380,8833,9138.55,1504745.517922
-1593561600000,9138.08,11444,8893.03,11335.46,1507827.21494
-1596240000000,11335.46,12468,10518.5,11649.51,1891193.007128
-1598918400000,11649.51,12050.85,9825,10776.59,1730389.160179
-1601510400000,10776.59,14100,10374,13791,1592634.419946
-1604188800000,13791,19863.16,13195.05,19695.87,2707064.911165
-1606780800000,19695.87,29300,17572.33,28923.63,2495281.856217
-1609459200000,28923.63,41950,28130,33092.98,3440864.750019
-1612137600000,33092.97,58352.8,32296.16,45135.66,2518242.148517
-1614556800000,45134.11,61844,44950.53,58740.55,2098808.027432
-1617235200000,58739.46,64854,46930,57694.27,1993468.938007
-1619827200000,57697.25,59500,30000,37253.81,3536245.256573
-1622505600000,37253.82,41330,28805,35045,2901775.305923
-1625097600000,35045,42448,29278,41461.83,1778463.264837
-1627776000000,41461.84,50500,37332.7,47100.89,1635402.874245
-1630454400000,47100.89,52920,39600,43824.1,1527799.510768
-1633046400000,43820.01,67000,43283.03,61299.8,1565556.292623
-1635724800000,61299.81,69000,53256.64,56950.56,1291900.105248
-1638316800000,56950.56,59053.55,42000.3,46216.93,1233745.524318
-1640995200000,46216.93,47990,32917.17,38466.9,1279407.465721
-1643673600000,38466.9,45821,34322.28,43160,1253514.21906
-1646092800000,43160,48189.84,37155,45510.34,1501398.79591
-1648771200000,45510.35,47444.11,37578.2,37630.8,1267655.68178
-1651363200000,37630.8,40023.77,26700,31801.04,2387839.680804
-1654041600000,31801.05,31982.97,17622,19942.21,2816058.473226
-1656633600000,19942.21,24668,18781,23293.32,4983278.5881
-1659312000000,23296.36,25211.32,19520,20050.02,5692462.41571
-1661990400000,20048.44,22799,18125.98,19422.61,9838930.53657
-1664582400000,19422.61,21085,18190,20490.74,7499121.81542
-1667260800000,20490.74,21480.65,15476,17163.64,9127693.509065
-1669852800000,17165.53,18387.95,16256.3,16542.4,5803833.88187
-1672531200000,16541.77,23960.54,16499.01,23125.13,7977028.87801
-1675209600000,23125.13,25250,21351.07,23141.57,8642691.27165
-1677628800000,23141.57,29184.68,19549.09,28465.36,9516189.35846
-1680307200000,28465.36,31000,26942.82,29233.21,1626745.5585
-1682899200000,29233.2,29820,25811.46,27210.35,1302000.49221
-1685577600000,27210.36,31431.94,24800,30472,1387207.48275
-1688169600000,30471.99,31804.2,28861.9,29232.25,925773.81731
-1690848000000,29232.26,30244,25166,25940.78,1025866.55023
-1693526400000,25940.77,27483.57,24901,26962.56,809329.04893
-1696118400000,26962.57,35280,26538.66,34639.77,1141403.6799
-1698796800000,34639.78,38450,34097.39,37723.96,1055690.59638
-1701388800000,37723.97,44700,37615.86,42283.58,1195409.976
-1704067200000,42283.58,48969.48,38555,42580,1403408.84978
-1706745600000,42580,64000,41884.28,61130.98,1206112.69545
-1709251200000,61130.99,73777,59005,71280.01,1706807.381342
-1711929600000,71280,72797.99,59191.6,60672,1201500.95852
-1714521600000,60672.01,71979,56552.82,67540.01,945031.04072
-1717200000000,67540.01,71997.02,58402,62772.01,696818.18818
-1719792000000,62772.01,70079.99,53485.93,64628,908004.33426
-1722470400000,64628.01,65659.78,49000,58973.99,1010291.47396
-1725148800000,58974,66498,52550,63327.59,734117.07575
-1727740800000,63327.6,73620.12,58946,70292.01,756010.86343
-1730419200000,70292.01,99588.01,66835,96407.99,1343559.242196
-1733011200000,96407.99,108353,90500,93576,1019450.065773
-1735689600000,93576,109588,89256.69,102429.56,864534.738322
-1738368000000,102429.56,102783.71,78258.52,84349.94,810850.1813
-1740787200000,84349.95,95000,76606,82550.01,845293.53101
-1743465600000,82550,95758.04,74508,94172,793597.00179
-1746057600000,94172,111980,93377,104591.88,642216.546125
-1748736000000,104591.88,110530.17,98200,107146.5,427546.46336
-1751328000000,107146.51,123218,105100.19,115764.08,484315.651017
-1754006400000,115764.07,124474,107350.1,108246.35,471366.942936
-1756684800000,108246.36,117900,107255,114048.93,374551.99407
-1759276800000,114048.94,126199.63,102000,109608.01,720300.285006
-1761955200000,109608.01,111250.01,80600,90360,784853.66178
-1764547200000,90360.01,94588.99,83822.76,87648.22,491084.34878
-1767225600000,87648.21,97924.49,75719.9,78741.09,491752.73296
-1769904000000,78741.1,79424,60000,66973.26,837887.67719
-1772323200000,66973.26,76000,65000,68284.48,705639.88404
-1775001600000,68284.49,79485.66,65712.12,76346.57,473256.46982

crates/wickra/examples/fetch_btcusdt.rs

@@ -2,8 +2,9 @@
 //! and write them as CSV datasets under `examples/data/`.
 //!
 //! These are the datasets the indicator benchmarks (`benches/indicators.rs`)
-//! and the `example_data` integration test run against. Re-run this example
-//! to refresh them with the latest market history:
+//! and the `example_data` integration test run against. They live at the
+//! workspace `examples/data/` directory. Re-run this example to refresh
+//! them with the latest market history:
 //!
 //! ```text
 //! cargo run -p wickra --example fetch_btcusdt
@@ -96,6 +97,8 @@ fn main() -> Result<(), Box<dyn Error>> {
         .map_err(|_| "system clock is beyond the i64 millisecond range")?;
 
     let data_dir = PathBuf::from(env!("CARGO_MANIFEST_DIR"))
+        .join("..")
+        .join("..")
         .join("examples")
         .join("data");
     std::fs::create_dir_all(&data_dir)?;

crates/wickra/tests/example_data.rs

@@ -2,11 +2,11 @@
 //! hold enough rows, and carry strictly increasing — and, for the fixed
 //! timeframes, evenly spaced — timestamps.
 //!
-//! The datasets live in `examples/data/` and are produced by the
-//! `fetch_btcusdt` example. Regenerate them with:
+//! The datasets live in the workspace `examples/data/` directory and are
+//! produced by the `fetch_btcusdt` example. Regenerate them with:
 //!
 //! ```text
-//! cargo run -p wickra --example fetch_btcusdt
+//! cargo run -p wickra-examples --bin fetch_btcusdt
 //! ```
 
 use wickra_data::csv::CandleReader;
@@ -26,7 +26,7 @@ const DATASETS: &[(&str, usize, Option<i64>)] = &[
 ];
 
 fn dataset_path(file: &str) -> String {
-    format!("{}/examples/data/{file}", env!("CARGO_MANIFEST_DIR"))
+    format!("{}/../../examples/data/{file}", env!("CARGO_MANIFEST_DIR"))
 }
 
 #[test]