fix(CLI-45): standardize the CLI credential env var and fail fast on empty passwords

All five client CLIs now share one credential contract for `authenticate-user`:
flags `--password` / `--password-env` (Go: `-password` / `-password-env`) with
default env `MXGATEWAY_VERIFY_PASSWORD`, resolution flag-then-env, and a resolved
credential that is missing *or empty* is a usage error naming the flag and the
variable. The value is never echoed and never reaches the wire.

Go and Java previously sent an empty credential when the variable was unset,
turning a misconfigured environment into a real MXAccess authentication attempt.
Go now returns the guard error before dialing; Java throws a picocli
ParameterException instead of falling back to "". Python's `--password-env`
gained the canonical default and its UsageError names the resolved variable.
Rust treats an empty flag or env value as missing, with the resolution extracted
into a testable `resolve_verify_user_password`. .NET adopts the canonical flags
and keeps `--verify-user-password`, `--verify-user-password-env`, and
MXGATEWAY_VERIFY_USER_PASSWORD as deprecated aliases for one release.

Docs same commit: CrossLanguageSmokeMatrix.md gains the credential contract and
the per-CLI subcommand-coverage table (the documented-not-fixed half of the
finding); all five READMEs name the canonical variable and the fail-fast rule,
and the .NET README carries the deprecation note. Tracking flipped to Done in
both remediation registers with a change-log row.

No .proto changed; no generated code regenerated.

archreview/2026-07-12/remediation/00-tracking.md

@@ -120,7 +120,7 @@ Full design + implementation for each row lives in the linked domain doc under i
 | CLI-42 | Low | P1 | S | — | Not started | Document the vendored Rust proto layout (CLI-02's missing doc half) |
 | CLI-43 | Low | — | S | — | Not started | Java style guide still prescribes "Java 21 preferred" |
 | CLI-44 | Low | — | S | — | Not started | Go event goroutine can mislabel a genuine terminal error as `ErrSlowConsumer` |
-| CLI-45 | Low | P1 | M | — | Not started | Standardize CLI credential env-var names; fail fast on missing/empty passwords |
+| CLI-45 | Low | P1 | M | — | Done | Standardize CLI credential env-var names; fail fast on missing/empty passwords |
 
 ### Testing, docs & gaps — [60-testing-docs-gaps.md](60-testing-docs-gaps.md)
 
@@ -164,3 +164,4 @@ Sequence these together rather than piecemeal — several are one change set spa
 | 2026-08-07 | **TST-29 → `Done`:** migrated the Phase-5 (orphan-worker reattach) deferred-not-planned governance record and the settled Phase-4 Viewer-default decision from `oldtasks.md` into a new "Session-Resilience Epic Scope" entry in `docs/DesignDecisions.md`; repointed CLAUDE.md and `stillpending.md:7,165` from `oldtasks.md` to `docs/DesignDecisions.md` / `docs/plans/2026-06-15-session-resilience.md.tasks.json`; `git rm oldtasks.md`. The five untracked root docs-review artifacts (`MxAccessGateway-docs-{issues,fixed,final}.md`, `MxGatewayClient-docs-{issues,fixed}.md`) were absent from this worktree — delete from the main working tree separately. |
 | 2026-08-07 | **GWC-24 → `Done`** (branch `fix/gwc-24-staging-bound`). `WorkerClient._eventStaging` is now `Channel.CreateBounded` at `2 × EventChannelCapacity` (`Wait`, single reader/writer, no sync continuations); a rejected staging `TryWrite` faults the client `ProtocolViolation` with `QueueOverflow("worker-event-staging")` unless `IsTerminalState()` (shutdown stays a silent drop), so a consumer draining slower than its worker produces dies at a fixed ceiling instead of growing gateway memory. Queue-depth accounting moved from `EnqueueWorkerEventAsync` to `StageWorkerEvent`, so the single gauge reports staged + queued; the timed-write fault (`EventChannelFullModeTimeout` / `QueueOverflow("worker-events")`) is unchanged and still catches the full-stall case first. No new config key — total gateway-side buffering is `3 × MxGateway:Events:QueueCapacity`, derived; coordination with still-open old **GWC-21** (`EventChannelFullModeTimeout` configurability) remains open and was not blocked on. Docs same commit: `GatewayProcessDesign.md` (two overflow faults), `MxAccessWorkerInstanceDesign.md`, `GatewayConfiguration.md`, `Metrics.md`. Tests: `WorkerClientTests.StagingChannelOverflowFaultsWorkerWithoutWaitingForFullModeTimeout` and `.WorkerEventQueueDepthGaugeCountsStagedEvents`; `WorkerClientTests` 22/22 green, `NonWindows.slnx` builds with 0 warnings. |
 | 2026-08-07 | **ReplayGap end-to-end cluster (GWC-25 + CLI-35 + CLI-36) → `Done`** on `fix/gwc-25-replaygap-trio`. GWC-25: `SessionEventDistributor.RegisterWithReplay`'s empty-ring branch now reports `oldestAvailableSequence = _highestSequenceSeen + 1` when `gap == true` (still `0` when no gap), so the universal `oldest - 1` resume formula no longer wraps to `ulong.MaxValue` and dead-stream the subscriber; `docs/Sessions.md` documents the empty-ring value. CLI-35: the Python CLI renders a `ReplayGap` as a `{"replayGap": {...}}` row via a new `_event_row` helper instead of crashing in `MessageToDict`. CLI-36: the Go CLI branches on `result.IsReplayGap()` and prints the typed `REPLAY_GAP requested_after=<n> oldest_available=<n>` line / `replayGap` JSON row instead of formatting the library's cleared `Event`. `docs/CrossLanguageSmokeMatrix.md` gained a per-CLI gap-rendering table (one edit covering both client findings). Four new tests as designed (3 × `SessionEventDistributorTests`, `GatewayEndToEndReconnectReplayTests.ReconnectAfterFullAgeEvictionResumesWithSentinelFormula`) plus `test_stream_events_renders_replay_gap` (Python) and `TestRunStreamEventsPrintsReplayGap` (Go); all written red first and each reproducing its defect verbatim. **Deferred:** GWC-25's `ReplayGap.oldest_available_sequence` proto-comment amendment is **not** in this change — it is comment-only but triggers the full five-client regen fan-out, so it lands with the later codegen wave (alongside IPC-23's proto-comment edits) rather than forcing a regen for one sentence. Note for that wave: the fake-worker gateway e2e suite cannot run on the macOS worktree without `TMPDIR` shortened (macOS caps the Unix-domain-socket path backing .NET named pipes at 104 chars; `TMPDIR=/tmp dotnet test …` works and was used here). |
+| 2026-08-07 | **CLI-45 → `Done`** on `fix/cli-45-credential-envvar`. All five CLIs now share one credential contract for `authenticate-user`: flags `--password` / `--password-env` (Go: `-password` / `-password-env`) defaulting to env `MXGATEWAY_VERIFY_PASSWORD`, resolution flag-then-env, and a resolved credential that is missing **or empty** is a usage error naming the flag and the variable — never the value, never sent to the wire. Go and Java previously authenticated with an empty password: Go now returns the guard error before dialing, Java throws a picocli `ParameterException` instead of falling back to `""`. Python's `--password-env` gained the canonical default (its `UsageError` was already conformant) and its message now names the resolved variable. Rust treats an empty `--password` or empty env value as missing (resolution extracted into a testable `resolve_verify_user_password`). .NET adopted the canonical flags and keeps its pre-existing names as **deprecated aliases for one release** — order: `--password`, `--verify-user-password`, the variable named by `--password-env` (or the deprecated `--verify-user-password-env`; default `MXGATEWAY_VERIFY_PASSWORD`), then `MXGATEWAY_VERIFY_USER_PASSWORD`. Tests: `TestRunAuthenticateUser{RejectsEmptyPassword,ReadsPasswordFromCanonicalEnv}` (Go), 3 picocli cases (Java), 3 click cases (Python), 2 clap/resolver cases (Rust), 4 xUnit cases covering the canonical flag, both env-name paths, the deprecated flag+env aliases, and the missing/empty failure (.NET). Docs same commit: `docs/CrossLanguageSmokeMatrix.md` gained a "Credential contract for `authenticate-user`" section **and** the per-CLI subcommand-coverage table — the half of this finding that is documented rather than fixed (.NET exposes all nine single-item session commands; Rust `unregister` + the credential pair; Go/Python/Java the credential pair only; verified against each dispatch table, and every gap is CLI surface only since all five *libraries* implement all nine helpers). All five client READMEs name the canonical variable and the fail-fast rule; the .NET README gained an `authenticate-user` credentials section carrying the deprecation note. **Deviation:** Java keeps `isBlank()` (per this design's "null or blank" wording for Java) where the other four test emptiness, so a whitespace-only credential is additionally rejected there. Verification (all five, on macOS): Go `gofmt -l .` clean, `go build ./...` clean, `go test ./...` ok; Java `JAVA_HOME=/opt/homebrew/opt/openjdk@17 gradle test` BUILD SUCCESSFUL, CLI suite 51 tests / 0 failures — **no generated-tree churn appeared this run**, `git status` for `clients/java/**/generated` clean with no revert needed (no `.proto` changed); Python `python -m pytest` 148 passed / 1 skipped (TLS opt-in); .NET `dotnet build …Client.slnx` 0 warnings / 0 errors and client tests 108 passed / 1 skipped (live-gateway opt-in); Rust `cargo fmt` (diff confined to the new code), `cargo check --workspace`, `cargo test --workspace` 100 tests across 6 targets all green, `cargo clippy --all-targets -- -D warnings` clean. |

archreview/2026-07-12/remediation/50-clients.md

@@ -26,7 +26,7 @@ Operating constraints carried from prior work:
 | CLI-42 | Low | P1 | S | — | Not started | Document the vendored Rust proto layout (CLI-02's missing doc half) |
 | CLI-43 | Low | — | S | — | Not started | Java style guide still prescribes "Java 21 preferred" |
 | CLI-44 | Low | — | S | — | Not started | Go event goroutine can mislabel a genuine terminal error as `ErrSlowConsumer` |
-| CLI-45 | Low | P1 | M | — | Not started | Standardize CLI credential env-var name and fail fast on missing/empty passwords |
+| CLI-45 | Low | P1 | M | — | Done | Standardize CLI credential env-var name and fail fast on missing/empty passwords |
 
 Cross-domain dependencies: **CLI-35/CLI-36 pair with GWC-25** (gateway emits `oldest_available_sequence = 0` on an empty replay ring — the server-side half of the same reconnect story; the CLI fixes here are independently landable but the end-to-end resume walk in the smoke matrix needs both). **CLI-39 pairs with the publishing process** (`scripts/pack-clients.ps1`, `scripts/tag-go-module.ps1`, Gitea package registry).