bench: fix the red runs, trim the matrix, add a grid job (#7)

Five consecutive red runs, two unrelated causes.

Four of them never reached an engine: the workflow installs the tag it is
handed, but 0.18.0rc1 and rc2 were previews that never reached PyPI.
Pre-releases are now skipped, and the report step checks for its input file
instead of dying on a missing one and reporting the wrong cause twice.

The fifth came from adding 10M bars, which broke a workload whose validity
depended on the ladder stopping at 5M. ema_rsi_fees sizes in fixed units and
pays 5 bps a side, so over 10M one-minute bars the fees compound into the whole
account: -15% of capital at 1M, -74% at 5M, exactly -100% at 10M, where fees
reach 99,611 of the 100,000 it started with. Both engines then sit at zero and
disagree by 9,085 round-trips about how many worthless trades to book on a dead
account. Workloads can now declare a ceiling, and the runner skips past it out
loud.

Fewer points per axis: three series lengths instead of five, a decade apart
each step. 10k measured the clock rather than the work, and 5M sat between two
points that already bracketed it. sma_cross crosses on 30/150 rather than
10/50, worth about 15% on the ratio because it books a third of the trades.

Grids get their own job, licensed through ci_activate.py, which refuses to run
unlicensed rather than time a wait. Three points, not a matrix: across the
plane the four-core ratio moves only between x32 and x38.

benchmarks/vs_vectorbt/workloads.py

@@ -59,6 +59,10 @@ class Workload:
     title: str
     why: str
     params: Dict[str, Any] = field(default_factory=dict)
+    # Longest series this workload is valid on, or None for no ceiling. A
+    # workload can stop being a comparison before it stops running: see the fee
+    # workload, whose account this exists to keep alive.
+    max_bars: int | None = None
     # Engine name -> Note. An engine with no entry here is expected to agree
     # with the reference down to float-reordering noise, and a disagreement is
     # a failure that withholds the timing.
@@ -70,11 +74,11 @@ WORKLOADS: Dict[str, Workload] = {
     for w in (
         Workload(
             key="sma_cross",
-            title="SMA 10/50 crossover, long-only, no cost",
+            title="SMA 30/150 crossover, long-only, no cost",
             why="The canonical baseline. Unambiguous indicator, no fee policy, "
                 "no stop semantics: if the engines disagree here, nothing else "
                 "in the suite is worth reading.",
-            params=dict(fast=10, slow=50, alloc=1.0),
+            params=dict(fast=30, slow=150, alloc=1.0),
         ),
         Workload(
             key="ema_rsi_fees",
@@ -87,6 +91,14 @@ WORKLOADS: Dict[str, Workload] = {
                 "engines on a wiped-out account compares rounding noise.",
             params=dict(fast=12, slow=26, rsi_period=14, rsi_lo=30.0, rsi_hi=70.0,
                         units=5.0, fee_bps=5.0),
+            # The account has to survive, or the engines are being compared on
+            # rounding noise around zero. Measured: -15% of capital at 1M bars,
+            # -74% at 5M, and exactly -100% at 10M, where fees reach 99,611 of
+            # the 100,000 started with. Past that the two disagree by thousands
+            # of round-trips while both sit at zero equity, which is a fact
+            # about a bankrupt strategy and not about either engine. The ceiling
+            # is set where the comparison still means something.
+            max_bars=1_000_000,
             notes={
                 "raptorbt": Note(
                     "unsupported",
@@ -110,7 +122,7 @@ WORKLOADS: Dict[str, Workload] = {
         ),
         Workload(
             key="sma_cross_metrics",
-            title="SMA 10/50 crossover, with a performance summary",
+            title="SMA 30/150 crossover, with a performance summary",
             why="The same simulation as `sma_cross`, but both engines are asked "
                 "for what a user actually reads: max drawdown, Sharpe, Sortino "
                 "and volatility alongside the return. manifoldbt computes them "
@@ -120,7 +132,7 @@ WORKLOADS: Dict[str, Workload] = {
                 "`sma_cross` above is the same work without the summary, and the "
                 "two are reported side by side so the reader can see what the "
                 "summary costs each engine.",
-            params=dict(fast=10, slow=50, alloc=1.0, metrics=True),
+            params=dict(fast=30, slow=150, alloc=1.0, metrics=True),
         ),
         Workload(
             key="bracket_sl_tp",