feat(family-11): add DeMark suite (TD Setup, Sequential, DeMarker, REI, Pressure) (#48)

* feat(family-11): add DeMark suite (TD Setup, Sequential, DeMarker, REI, Pressure)

Family 11 (DeMark) was previously empty; this PR adds five
streaming-first DeMark indicators in one batch.

- **TD Setup** (`TdSetup`): parameterised buy/sell setup counter.
  Counts consecutive bars whose close is less-than (buy) or
  greater-than (sell) the close `lookback` bars earlier, saturating
  at `target`. Emits a signed `f64` so callers read direction from
  the sign and run length from the magnitude. Classic config:
  `lookback = 4`, `target = 9`.

- **TD Sequential** (`TdSequential`): the canonical Setup + Countdown
  exhaustion pattern. Output struct `{ setup, countdown, direction }`
  exposes both phase counts as signed numbers plus the active
  countdown direction (+1 buy / -1 sell / 0 none). Countdown
  activates when a setup completes and tracks the close-vs-high/low
  comparison `countdown_lookback` bars back, capped at
  `countdown_target`. Classic: 4/9/2/13.

- **TD DeMarker** (`TdDeMarker`): bounded [0, 1] oscillator from the
  rolling average of upward high expansion (DeMax) and downward low
  expansion (DeMin). Falls back to the neutral 0.5 on a flat market
  (denominator zero).

- **TD REI** (`TdRei`): Range Expansion Index, bounded [-100, 100].
  Per-bar numerator gated on a range-overlap condition vs the bars
  5 and 6 back, normalised by a `period`-bar sum of absolute moves.
  Classic period = 5. Saturates at +100 in a slow steady uptrend
  and at -100 in the mirror downtrend; emits 0 on a flat market.

- **TD Pressure** (`TdPressure`): volume-weighted buying / selling
  pressure normalised to [-100, 100]. Per-bar pressure is the
  intra-bar close-vs-open ratio scaled by volume; the output is the
  rolling mean divided by the rolling mean volume. Zero-range bars
  contribute zero (avoid the undefined ratio) and a flat zero-volume
  window falls back to 0.

Bindings: all five exposed in Python (`ta.TDSetup`, `ta.TDSequential`,
`ta.TDDeMarker`, `ta.TDREI`, `ta.TDPressure`), Node (`wickra.TDSetup`
etc.), and WASM. Multi-output classes (`TDSequential`) return either
a struct `{ setup, countdown, direction }` per bar (streaming) or a
flat interleaved Float64Array of length `3 * n` (batch).

Tests: 47 unit tests across the five new core files (pure-trend
saturation, flat-market neutral fallback, batch-equals-streaming,
zero-parameter rejection, reset semantics, accessors). Python
test_new_indicators.py picks up all five plus a multi-output TD
Sequential block. Node indicators.test.js picks up all five.
Reference values added to test_known_values.py.

Fuzz: candle fuzz target sweeps all five DeMark indicators with the
existing `Vec<f64>` -> `Vec<Candle>` driver.

Benches: BTCUSDT 1-minute dataset benches for each DeMark indicator
in `crates/wickra/benches/indicators.rs`.

Docs: README family table gains a "DeMark" row; indicator counter
bumped 71 -> 76. CHANGELOG entry added under [Unreleased]. Wiki
drafts (deep-dive pages + Sidebar / Overview / Warmup-Periods / Home
deltas) live under `indicator-ideas/families/wiki/family-11-demark/`
for manual merge into the wiki repo.

* feat(family-11): add 7 missing DeMark indicators

Complete the DeMark suite (family 11) with the seven indicators not
covered by the first commit: TD Combo, TD Countdown, TD Lines (TDST),
TD Range Projection, TD Differential, TD Open, and TD Risk Level.

- TdCombo: aggressive countdown variant with three strictness rules
  on top of the classic close-vs-low/high lookback rule (monotone
  low/high, monotone close vs prior bar).
- TdCountdown: standalone 13-bar countdown packaging only the signed
  countdown count (the setup machine runs internally).
- TdLines: TDST horizontal support/resistance levels from the
  highest-high / lowest-low bars of the most-recently-completed
  setup, exposed as a multi-output struct.
- TdRangeProjection: DeMark X-projection of the next bar's high and
  low from the current bar's OHLC via an open-vs-close-weighted
  pivot (three branches: close<open, close>open, close==open).
- TdDifferential: two-bar buying-pressure vs selling-pressure
  reversal pattern emitting +1/-1/0.
- TdOpen: gap-and-fade reversal pattern (open outside prior range
  with subsequent recovery into it) emitting +1/-1/0.
- TdRiskLevel: protective stop levels derived from the setup
  extreme bar +/- its true range.

All seven are wired through Rust core, Python, Node and WASM
bindings, registered in the candle-stream fuzz target, given
benchmark entries on the BTCUSDT 1-minute dataset, and covered by
streaming-vs-batch equivalence, reference-value, lifecycle and
input-validation tests on the Python and Node sides. README counter
moves 76 -> 83 and the CHANGELOG "family 11" entry is extended to
list all twelve indicators.

* fix(td_risk_level tests): check first emission at idx 12, not last bar

TdRiskLevel re-ratchets the sell-risk level on each subsequent setup
completion, so a strictly rising series produces 22.0 at idx 19 (latest
setup) rather than 15.0 (first setup). The test comment already named
idx 12 as the reference; switch the assertion from out[-1] to out[12]
to match the reference computation.

* test(family-11): cover buy-direction branches in TD indicators

Add downtrend tests to TdSequential, TdCombo and TdCountdown so the
buy-side countdown/combo increment branches are exercised; remove an
empty `if buy_countdown == target {}` block in TdSequential whose
behavior is already enforced by the outer strict `<` guard.

Closes codecov/patch gaps reported on PR #48 (10 missed lines across
the three files).

bindings/node/__tests__/indicators.test.js

@@ -145,6 +145,14 @@ const candleScalar = {
   GarmanKlassVolatility: { make: () => new wickra.GarmanKlassVolatility(20, 252), step: (ind, i) => ind.update(open[i], high[i], low[i], close[i]), batch: (ind) => ind.batch(open, high, low, close) },
   RogersSatchellVolatility: { make: () => new wickra.RogersSatchellVolatility(20, 252), step: (ind, i) => ind.update(open[i], high[i], low[i], close[i]), batch: (ind) => ind.batch(open, high, low, close) },
   YangZhangVolatility: { make: () => new wickra.YangZhangVolatility(20, 252), step: (ind, i) => ind.update(open[i], high[i], low[i], close[i]), batch: (ind) => ind.batch(open, high, low, close) },
+  TDSetup: { make: () => new wickra.TDSetup(4, 9), step: (ind, i) => ind.update(high[i], low[i], close[i]), batch: (ind) => ind.batch(high, low, close) },
+  TDDeMarker: { make: () => new wickra.TDDeMarker(14), step: (ind, i) => ind.update(high[i], low[i]), batch: (ind) => ind.batch(high, low) },
+  TDREI: { make: () => new wickra.TDREI(5), step: (ind, i) => ind.update(high[i], low[i]), batch: (ind) => ind.batch(high, low) },
+  TDPressure: { make: () => new wickra.TDPressure(5), step: (ind, i) => ind.update(open[i], high[i], low[i], close[i], volume[i]), batch: (ind) => ind.batch(open, high, low, close, volume) },
+  TDCombo: { make: () => new wickra.TDCombo(4, 9, 2, 13), step: (ind, i) => ind.update(high[i], low[i], close[i]), batch: (ind) => ind.batch(high, low, close) },
+  TDCountdown: { make: () => new wickra.TDCountdown(4, 9, 2, 13), step: (ind, i) => ind.update(high[i], low[i], close[i]), batch: (ind) => ind.batch(high, low, close) },
+  TDDifferential: { make: () => new wickra.TDDifferential(), step: (ind, i) => ind.update(high[i], low[i], close[i]), batch: (ind) => ind.batch(high, low, close) },
+  TDOpen: { make: () => new wickra.TDOpen(), step: (ind, i) => ind.update(open[i], high[i], low[i], close[i]), batch: (ind) => ind.batch(open, high, low, close) },
 };
 
 for (const [name, d] of Object.entries(candleScalar)) {
@@ -200,6 +208,11 @@ const multi = {
   DemarkPivots: { make: () => new wickra.DemarkPivots(), fields: ['pp', 'r1', 's1'], step: (ind, i) => ind.update(open[i], high[i], low[i], close[i]), batch: (ind) => ind.batch(open, high, low, close) },
   WilliamsFractals: { make: () => new wickra.WilliamsFractals(), fields: ['up', 'down'], step: (ind, i) => ind.update(high[i], low[i]), batch: (ind) => ind.batch(high, low) },
   ZigZag: { make: () => new wickra.ZigZag(0.02), fields: ['swing', 'direction'], step: (ind, i) => ind.update(high[i], low[i]), batch: (ind) => ind.batch(high, low) },
+  // Family 11: DeMark
+  TDSequential: { make: () => new wickra.TDSequential(4, 9, 2, 13), fields: ['setup', 'countdown', 'direction'], step: (ind, i) => ind.update(high[i], low[i], close[i]), batch: (ind) => ind.batch(high, low, close) },
+  TDLines: { make: () => new wickra.TDLines(4, 9), fields: ['resistance', 'support'], step: (ind, i) => ind.update(high[i], low[i], close[i]), batch: (ind) => ind.batch(high, low, close) },
+  TDRangeProjection: { make: () => new wickra.TDRangeProjection(), fields: ['high', 'low'], step: (ind, i) => ind.update(open[i], high[i], low[i], close[i]), batch: (ind) => ind.batch(open, high, low, close) },
+  TDRiskLevel: { make: () => new wickra.TDRiskLevel(4, 9), fields: ['buyRisk', 'sellRisk'], step: (ind, i) => ind.update(high[i], low[i], close[i]), batch: (ind) => ind.batch(high, low, close) },
 };
 
 for (const [name, d] of Object.entries(multi)) {