v0.4.0 — adoption-surface batch

Theme: Adoption surface — scriptable chat, friendlier errors, completed CRUD.

Three focused features that close the v0.4.0 Tier 2 plan (D-050 / D-051 /
D-052). All three target adoption: making the CLI usable from scripts /
CI, making transport failures self-actionable, and completing the gaps
in the engagement-entity verbs that previous releases left behind.

Added

• D-050 — praxis chat --message/-m "..." runs one turn through
  the full ChatRuntime (tools, session, slash commands) and exits 0.
  The REPL banner is suppressed so stdout stays clean for callers piping
  into jq or similar. PII guard (D-043) still fires on the single
  turn. Difference vs. praxis ask: chat -m keeps the runtime, so the
  agent can call engagement / queue tools; ask is stateless.

• D-052 — Completed CRUD verbs on praxis engagement assumption
  and praxis engagement constraint:

  • assumption get|update|remove
  • constraint get|update|remove

  Updates are partial (only supplied flags are written) and preserve
  untouched fields including the validated flag on assumptions. Both
  get variants support --json for scripting. Closes NEW-001.

• D-052 — praxis engagement question open now accepts
  --answerers <stakeholder-ids> and --blocks <artifact-ids> (both
  comma-separated). The repo accepted these fields since 0.2.x; only
  the CLI binding was missing. Closes NEW-004.

Changed

• D-051 — Transport errors are now provider-specific and actionable.
  New praxis.transport.errors.translate_provider_exception() duck-types
  on type(exc).__module__ + class name (both OpenAI and Anthropic
  SDKs share the Stainless-generated exception hierarchy) and maps each
  kind to a tailored message:

  • auth → names the env var to set
  • permission → names the model the key lacks access to
  • rate_limit → suggests retry / tier upgrade
  • not_found → names the missing model
  • bad_request → carries the SDK's detail
  • server_error → tells the user to retry later
  • connection → blames the network with the SDK's detail
  • timeout → identifies a timed-out request

  Each TransportError carries details["kind"] so future retry logic
  can branch programmatically without string-matching. Unknown
  exceptions fall through to today's generic message — behaviour is
  strictly additive, no existing assertion breaks. Closes
  NEW-003.

Breaking (CLI)

• D-050 — praxis chat --model no longer accepts the -m short
  alias. -m is now bound to --message, matching git commit -m and
  praxis queue commit -m convention. The full --model gpt-4.1
  long form still works. --model -m is intact on artifact, check,
  and elicit (those have no --message conflict).

Documentation

• D-050 — docs/how-to/first-engagement.md gains a "Scripting and
  CI" section with a chat -m vs ask comparison table.

Quality

• 571 tests passing (+32 since v0.3.1), coverage 84.42%.
• All four gates green per commit: pytest, ruff check,
  ruff format, mypy --strict src/praxis.
• 5 conventional commits since v0.3.1 (D-050 ×2 / D-051 / D-052 + bump).

Known limitations / deferred to v1.0.0

• D-055 — Multi-engagement awareness (praxis engagements list/ show/switch, registry, TUI header) deferred. Larger feature; queued
  for a dedicated cycle.
• D-053 / D-054 / D-056 — Superseded by v1.0.0 plan items
  (D-067 TUI regenerate, D-062 pilot tests, D-066 doctor expansion).
  See ~/praxis-realworld-eval/v1.0.0-plan.md in the eval workspace.