feat(DEN-1444): land native schema-v2 task runtime on current main

[ORESoftware]

Scope

Replaces stale draft #148 and materializer-only #164 with an ordinary current-main product branch for the first manager-neutral schema-v2 task runtime.

Exact product head

3452a2faaebbc9e0f74f71c98110f06fb94f09ad

This head is tree-identical to finalized source commit 1db694684ad479112390aa10e62c1d4014f375f3. The additional commit is an app-authored attestation so normal pull-request workflows run against the exact final tree rather than remaining action_required on the bot-authored self-removal commit.

The foundational semantic merge preserves:

1. exact main at 0c1931bcdc2065279aea06abe9d66a0eb9e03315; and
2. the fully reviewed task-runtime history at 38c2acfd42968d5ba21c65f5e1a42bcad5928d82.

Current main has not advanced beyond that merge base. The final branch is mergeable and contains exactly seven ordinary product paths.

Exact seven-file delta

• .github/workflows/task-runtime.yml
• .task-cli-flags.toml
• docs/task-runtime.md
• src/bin/zed-task.rs
• src/lib.rs
• src/task_runtime.rs
• tests/task_runtime_cli.rs

No temporary finalizer, trigger, branch-writing workflow, or materialization script remains.

Commands

zed-task [--plan zed-env.toml] list [--all]zed-task [--plan zed-env.toml] info <task>zed-task [--plan zed-env.toml] graph <task>zed-task [--plan zed-env.toml] run <task> [--dry-run] [--yes] [--jobs N] [--no-cache] [-- <args>...]

Semantics

• validated task and alias lookup;
• depends, wait_for, and depends_post ordering;
• nested invocations and sequential/bounded-parallel groups;
• POSIX/Windows command variants and exact child status propagation;
• scalar top-level, task, and invocation environment precedence;
• project-local working directories with symlink containment;
• confirmations, dry-run, timeouts, deterministic reports, and typed argument environment metadata;
• content-verified incremental caching over plan/task/input/output identity; and
• fail-closed rejection of unsupported tool overlays, templates, structured process values, unsafe paths, zero concurrency, and malformed cache state.

Validation completed before final tree attestation

The self-removing finalizer completed successfully and deleted itself after running:

• rustfmt and git diff --check;
• task_runtime library tests;
• compiled zed-task CLI tests;
• asdf command integration;
• Nix/Devbox/Flox environment export integration;
• frozen-offline prefetch integration;
• global command integration; and
• strict Clippy for the task binary and CLI test.

The first finalizer attempt exposed a fixture typo: the shared schema field is depends_post, not depends-post. The graph implementation already handled depends_post; the canonical fixture was corrected and the unchanged graph assertion passed on the successful run.

The permanent workflow is read-only, checks out the exact candidate, runs on Ubuntu 24.04, macOS 15, and Windows 2025, validates the flags-to-environment contract, and repeats deterministic dry-run output. All ordinary repository workflows are now queued/running on the exact app-authored head above.

Do not merge until every exact-head workflow is terminal-successful and no review threads or change requests remain.

Linear: DEN-1444, DEN-1435
Supersedes: #148, #164

[linear-code]

DEN-1444