0.9.2 architecture deletion audit

This file is the reconstruction ledger for the 0.9.2 release branch. It is a deletion audit, not a compatibility roadmap. A release change is complete only when the superseded runtime is absent, the remaining boundary is explicit, and one contract suite proves that boundary.

Target architecture

1. Task v2 exists only as input to the explicit akm migrate command. Normal task load, run, scheduler, and projection accept task v3 only.
2. Markdown and GitHub-shaped YAML workflow sources compile to source IR v1. Source IR freezes to durable plan IR v4 and one workflow engine executes it.
3. Durable plan IR v4 is the only executable stored workflow plan. Pre-v4 plans are rejected; there is no compatibility decoder or replay engine.
4. Command, task, and workflow execution share one resolver and lowering pipeline. Old dispatchers are deleted rather than wrapped.
5. Configuration and database schemas are current-only runtime contracts. Exact-prefix additive state DDL and the verified data-preserving migration 002 rebuild run automatically. Historical destructive migration 018 requires successful akm upgrade intent and one verified sibling safety snapshot; an already-existing unversioned file (with an absent or empty migration ledger) likewise requires a verified snapshot before migration 001, with one writer lock retained through ledger initialization and migrations 001–002. There is no general storage migration framework.
6. Semantic inference uses the ordinary external @huggingface/transformers dependency. AKM does not copy that package into src/vendor or dist/vendor, pin its transitive runtime layout, or carry a second installed-consumer dependency policy.
7. Tests pin each public boundary once. Fault tests remain where they prove a distinct safety invariant; characterization and surface-by-surface copies do not.

Kept boundaries

Deleted architecture

Active audit

The following work remains before this branch is release-ready:

• audit remaining source modules for old dispatchers or compatibility aliases closed out by P4 §3 (docs/plans/specs/p4-deletions-closeout.md). P4's three deletion families were exactly this: the GitHub Action locator grammar (a recognized-but-dead dispatcher variant), task source v3 acceptance and its P1b/P2b compat shims (src/tasks/runtime-v3.ts, src/tasks/runner.ts, src/workflows/ir/source-freeze-v4.ts, src/tasks/source/parse-v3-adapter.ts, src/tasks/model/{definition,schedule}.ts), and the multi-job parse/ordering machinery (src/workflows/source-ir/ordering.ts). Each family ran a zero-consumer grep before deleting (pasted into its own commit body) and a post-deletion sweep after; the Size checkpoint section below has each family's own src/ shortstat and file list. Confirmed still-zero at this checkpoint: rg -n 'github-action|remote-action-acquisition|isGithubLocatorShape|GITHUB_OWNER' src/ schemas/, rg -n 'parseTaskV3Yaml|parseTaskV3Document|classifyTaskV3Uses|TASK_V3_SCHEMA_VERSION' src/, rg -n 'canonicalTopologicalJobs|job-count-limit|missing-job-dependency|job-dependency-cycle|duplicate-job-dependency|exactly one source-IR job|Multi-job workflow cannot execute' src/. One item remains and is deliberately not folded into this close-out: §8 row R-R1 (P3a §0, P3b §0) defers renaming schema-v4.ts / freeze-v4.ts / environment-v4.ts and the TaskV3* / PreparableTaskDocument type family to a follow-up commit, on the binding rationale that a rename storm across ~40 import sites would bury the deletion diff this checkpoint exists to prove. That is a naming cleanup, not a live dispatcher or compatibility alias — nothing on that list still branches on a retired grammar or version — so it is real remaining work, named here rather than dropped, without reopening this bullet.
• run architecture-focused tests, full unit/integration checks, build, package closure, and release checks on one immutable candidate.

Scheduler-backend consolidation is complete and independently approved. One shared conformance matrix covers cross-platform CAS/ownership/rollback behavior, including zero native mutations on rejected operations; backend-local parsing, encoding, stabilization, compensation, and fault cases remain.

Size checkpoint

Branch-level, git diff --shortstat origin/release/0.9.2...HEAD (measured at commit 120e1c0b; re-measure before any later commit changes the diff):

The three path rows do not sum to the overall row — a file changed outside all three globs (CHANGELOG.md, STABILITY.md, README.md, schemas/**, and similar repo-root/schema files are common in a docs-and-vocabulary close-out phase) is counted in the overall row and in none of the three, and git diff --shortstat's own file count is not a per-glob sum in any case.

The prior checkpoint's figure — against origin/main, commit 092400a19, net +33,075 (+79,209/-46,134) — no longer reproduces and was never comparable to begin with: it measured a different base branch (origin/main, not origin/release/0.9.2, the actual release this work diffs against) at a much earlier commit, before P3a, P3b, and P4 landed. Re-measured against the correct base at this checkpoint, the true figure is net +45,291 (+51,222/-5,931).

Deletions this phase lands — one row per §3 family (docs/plans/specs/p4-deletions-closeout.md), each git diff --shortstat <family-parent>..<family-commit> -- src/:

src/tasks/source-v3.ts is not on either deleted-file list — per §0 (R-R1) it shrinks in place and keeps its name (further shrunk again, outside these three families, by this same review-fix pass's finding 4: a dead export { UsageError } and its supporting import). A2's insertions (+638) exceed a pure deletion because the same commit adds the vendored frozen migrator parser (scripts/akm-migrate/migrate/task-source-v3-frozen.ts, outside src/) and the new src/workflows/source-ir/triggers.ts that classifyTaskV3Triggers re-homes into (§3.2.3/P4-N3) — both required additions, not incidental growth.

The audit's own rule, restated: deletions must show. src/ is still net-positive against origin/release/0.9.2 — +6,676 lines (+10,776/-4,100) — and that is expected, not a shortfall. P2 and P3 added real, load-bearing capability release/0.9.2 did not have: task source v4 (typed inputs: with defaults/validation, a single bounded output: schema, per-schedule enabled), the input-binding contract shared between task and workflow params, child workflows (direct and task-wrapped composition, recursive freeze, independent resume, cancellation propagation, composition bounds), workflow outputs:, source IR v1 (the Markdown and GitHub-shaped YAML adapters plan irVersion 5 compiles from), the phase-specific UsageErrorCode family (D7, 38 codes' worth of task/workflow domain diagnostics), and two new introspection verbs (akm task explain, akm workflow plan). P4's three deletion families above removed real dead weight — the GitHub Action locator grammar, task source v3's parser and its P1b/P2b compat shims, and the multi-job parse/ordering machinery — but no version of this refactor was ever going to make src/ net-negative against the pre-refactor release while also shipping child workflows and a new task source generation. Claiming otherwise would be the hand-waved "significantly reduced" this section is bound not to write.