Fuaran.Core.DataFrame 0.26.0

Fuaran.Core.Column.Ops — a columnar op-algebra over Fuaran.Core.Column's Table (SetCell / SetColumn / InsertColumn / RemoveColumn / AppendRows / ApplyTransform) with a total apply / canApply, a partial invert (undo/redo), a structural Diff, a canonical wire codec, and a Fuaran.Core.OpStream StreamWitness — so table edits become an append-only, hash-chained, replayable, tamper-evident stream (the columnar analogue of the tree op-stream). No base type, no new witness field (the op DU is self-contained over Table; OpStream stays generic over its (apply, encode, decode) witness). FSharp.Core only, Fable-clean.

Drift detector for Fuaran op-apply telemetry. Computes per-OpKind aggregate metrics (success rate, p50/p95 latency, top decoder-rejection reasons, top NodeNotFound NodeIds) and flags week-on-week success-rate regressions exceeding an operator-tunable threshold (default 10pp). Also ships a deterministic StyleFlag drift detector (Phase 151) — the resolved-style twin that diffs declared-invariant flag sets across two windows of StyleObservation to surface newly-introduced / cleared visual-legibility violations, severity-weighted by the ThemeManifest's invariant weights (semantic visual regression, no pixels, CI-gateable). Manual-run console tool for now (`dotnet run --project src/Fuaran.UI.Telemetry.Drift`); cron-friendly later when an operator-decided threshold is wired into a scheduled job. Companion to Fuaran.UI.Telemetry.Abstractions. Apache-2.0 licensed.

Fuaran.Program.Bounded — the bounded program interpreter: a total fold of the wire-representable action set over a program's state store, with the no-closure-invocation invariant that makes an emitted tree safe to run untrusted. Placement-neutral by construction (the same interpreter drives a server session and a browser client), plus the server placement's loop with its per-interaction resource budget. Apache-2.0 licensed.

Fuaran.Program.Server — the server-logic placement of the bounded program loop: run a named, host-registered handler as data behind a program tree's call action, with a closed server-effect vocabulary (query, op-apply, host call, patch, notify) behind a default-deny gate. Shares the interpreter, the resource budget and the binding re-resolution pass with the other placements rather than reimplementing them. Carries the codec for the handler declared form, the effect vocabulary and the outcome report, certified against their own conformance corpus. Apache-2.0 licensed.

Fuaran.Core.DataFrame.Conformance — the law families over the dataframe layer, beside the Fuaran.Core.Conformance kit they extend: transform parity against the DataFrame reference evaluator, the columnar op-algebra and op-stream (ColumnOps), incremental evaluation (evalFrom and the IncrementalDelta equivalence family), params and slot params, the static output-schema walk, the pinned evaluation clock, and aggregate-versus-GroupBy parity. The families ship in module DataFrameConformance; the pre-split Conformance.* spellings forward to them (marked for removal in Phase 258). FSharp.Core only, Fable-clean.