feat(schedule): tinyflows-schedule crate (schedule model + next-run logic)

CHANGELOG.md

@@ -9,6 +9,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- **`crates/tinyflows-schedule`** — the schedule model (`Schedule`,
+  `ActiveHours`, the job/run records) and its pure logic: cron-expression
+  normalisation, time-zone and active-window aware next-run computation,
+  validation and the minimum-cadence check. Extracted from OpenHuman's `cron`
+  domain; the serde shapes are byte-identical and pinned by literal-JSON
+  fixtures. No runtime, store or config.
 - **`tinyflows_catalog::graph_hash::compute_graph_hash`** — the content pin over
   a graph plus its `require_approval` flag that a parked run records and a
   resume re-checks. Extracted from OpenHuman; the digest is byte-identical to

CLAUDE.md

@@ -26,6 +26,7 @@ uses, so a reader who knows one knows them all.
 | `crates/tinyflows-sqlite` | SQLite implementations of the catalog and of the engine's checkpoint store, plus the JSON draft store. Every entry point takes a directory, never a host config type. |
 | `crates/tinyflows-copilot` | The authoring copilot's *words*: the `workflow_builder` / `flow_discovery` standing archetypes, and the turn brief that opens a builder turn. Names no tool trait, no agent registry, no model client. |
 | `crates/tinyflows-adaptive` | The adaptive loop over the engine: select or author a workflow, run it, judge it, learn. |
+| `crates/tinyflows-schedule` | Schedule model and pure next-run logic (cron / interval / one-shot, time zones, active hours, cadence floor). No runtime, store or config. |
 
 **Where a new thing goes.** Ask what it depends on, not what it is about. If it
 needs storage, it is not `tinyflows-catalog`. If it needs a tool trait or a model

crates/tinyflows-schedule/Cargo.toml

@@ -0,0 +1,28 @@
+# Pure scheduling logic for timed jobs: the `Schedule` / `ActiveHours` model
+# (with its persisted wire shape), cron-expression normalisation, time-zone and
+# active-window aware next-run computation, and the minimum-cadence check.
+#
+# Deliberately no scheduler runtime, store, clock or config here: a host owns
+# when to poll, where jobs are kept and what a run does. This crate only
+# answers "given this schedule and this instant, when next?".
+[package]
+name = "tinyflows-schedule"
+version = "0.1.0"
+description = "Cron/interval/one-shot schedule model and next-run computation for tinyflows hosts"
+edition.workspace = true
+rust-version.workspace = true
+license.workspace = true
+repository.workspace = true
+homepage.workspace = true
+readme = "../../README.md"
+
+[dependencies]
+serde = { workspace = true }
+chrono = { workspace = true }
+anyhow = "1.0"
+cron = "0.12"
+chrono-tz = "0.10"
+tracing = { workspace = true }
+
+[dev-dependencies]
+serde_json = { workspace = true }

crates/tinyflows-schedule/src/lib.rs

@@ -0,0 +1,24 @@
+//! Scheduling model and next-run computation for timed jobs.
+//!
+//! * [`types`] — [`Schedule`], [`ActiveHours`] and the job/run records a host
+//!   persists. Their serde shapes are a wire contract (a host's job store and
+//!   RPC surface carry them), pinned by `wire_tests`.
+//! * [`schedule`] — next-run computation, validation, cron-expression
+//!   normalisation and the minimum-cadence check.
+//!
+//! No runtime, storage or configuration lives here; a host supplies those.
+
+pub mod schedule;
+pub mod types;
+
+pub use schedule::{
+    MIN_AGENT_JOB_INTERVAL, TooFrequent, next_run_for_schedule, normalize_expression,
+    runs_closer_than, schedule_cron_expression, validate_agent_schedule, validate_schedule,
+};
+pub use types::{
+    ActiveHours, CronJob, CronJobPatch, CronRun, DeliveryConfig, JobType, Schedule, SessionTarget,
+};
+
+#[cfg(test)]
+#[path = "wire_tests.rs"]
+mod wire_tests;