feat(voyage): S18 — framing-hardening (min-version gate + memory status + pre-2.2 doc + flagship hedge)

Closes devils-advocate audit #4–#6 (MAJOR×MED). Four additive, non-breaking
changes to the v5.5 framing-alignment machinery:

1. --min-brief-version <ver> gate (audit #4). Opt-in version floor on
   /trekplan + /trekresearch, forwarded to brief-validator as --min-version.
   New opts.minBriefVersion warns BRIEF_VERSION_BELOW_MINIMUM (never blocks)
   when a brief declares a version below the floor; trekreview exempt; absent
   opt = no check. CLI shim parses --min-version and skips its value token in
   filePath detection.

2. memory_alignment.status field (audit #5). brief-reviewer now emits
   status: verified | n_a | contradictions so a score-5 N/A (no memory) is
   distinguishable from a score-5 verified-aligned brief — the score≥4 gate
   passes in both, status reveals whether the wrong-premise defense ran.

3. Document pre-2.2 = zero framing enforcement (audit #4). HANDOVER-CONTRACTS
   §Handover 1 now states the producer-elective hole + two remedies. Also
   fixes a stale "current is 2.1" line (current is 2.2).

4. Soften flagship overselling (audit #6). CLAUDE.md Context-Engineering
   principle now hedges that main-context relief is asserted-by-design, not
   measured (T1 PoC found Δ≈0); README carried no false claim to fix.

TDD: 8 new tests written failing-first (5 validator, 1 trekbrief status pin,
2 doc-consistency cross-file pins). Suite 691→699 (697 pass / 2 skip / 0 fail).
No flagship prose-pin added (deliberate, per S19 anti-bloat).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LqBYc8Ltrk7LipyJmGxXiB

commands/trekplan.md

@@ -63,8 +63,11 @@ Parse `$ARGUMENTS` for mode flags. Order of precedence:
    - Set **project_dir = {dir}**, **brief_path = {dir}/brief.md**.
    - **Validate inputs** (soft mode — warnings do not block, errors do):
      ```bash
-     # Brief schema sanity check (frontmatter + state machine, soft on body sections)
-     node ${CLAUDE_PLUGIN_ROOT}/lib/validators/brief-validator.mjs --soft --json "{dir}/brief.md"
+     # Brief schema sanity check (frontmatter + state machine, soft on body sections).
+     # When --min-brief-version was passed, append --min-version {min_brief_version}
+     # so the validator emits BRIEF_VERSION_BELOW_MINIMUM (warn, never block) for an
+     # older brief that sidesteps framing enforcement.
+     node ${CLAUDE_PLUGIN_ROOT}/lib/validators/brief-validator.mjs --soft --json [--min-version {min_brief_version}] "{dir}/brief.md"
 
      # v5.1.1 — resolve per-phase brief-signal for plan phase. Result is
      # captured as phase_signal_result and used at Agent-spawn sites below
@@ -120,7 +123,15 @@ Parse `$ARGUMENTS` for mode flags. Order of precedence:
    autonomy-gate state machine via the CLI shim:
    `node ${CLAUDE_PLUGIN_ROOT}/lib/util/autonomy-gate.mjs --state X --event Y --gates {true|false}`.
 
-9. If neither `--brief` nor `--project` is present after flag parsing,
+9. **`--min-brief-version <ver>`** — (optional) version floor. Set
+   **min_brief_version = {ver}** (e.g. `2.2`). Forwarded to the brief-validator
+   as `--min-version {ver}`; when the brief declares an older version it emits a
+   `BRIEF_VERSION_BELOW_MINIMUM` **warning** (never blocks) — framing enforcement
+   only fires at `≥ 2.2`, so an older brief sidesteps the framing-alignment
+   defense silently. Absent → no version check. See `docs/HANDOVER-CONTRACTS.md`
+   §Handover 1 for the pre-2.2 enforcement hole this guards.
+
+10. If neither `--brief` nor `--project` is present after flag parsing,
    output usage and stop:
 
 ```
@@ -140,6 +151,7 @@ Modes:
   --research    Add up to 3 extra research briefs as planning context
   --fg          No-op alias (foreground is the only mode as of v2.4.0)
   --quick       Skip exploration agent swarm; plan directly
+  --min-brief-version <ver>  Warn (never block) if the brief is older than <ver> (e.g. 2.2)
   --export      Generate shareable output from an existing plan (no new planning)
   --decompose   Split an existing plan into self-contained headless sessions
 

commands/trekresearch.md

@@ -60,7 +60,9 @@ Supported flags:
    at Agent-spawn sites in Phase 4 to inject the brief-resolved model:
 
    ```bash
-   node ${CLAUDE_PLUGIN_ROOT}/lib/validators/brief-validator.mjs --soft --json "{dir}/brief.md"
+   # When --min-brief-version was passed, append --min-version {min_brief_version}
+   # so an older brief raises BRIEF_VERSION_BELOW_MINIMUM (warn, never block).
+   node ${CLAUDE_PLUGIN_ROOT}/lib/validators/brief-validator.mjs --soft --json [--min-version {min_brief_version}] "{dir}/brief.md"
    node ${CLAUDE_PLUGIN_ROOT}/lib/profiles/phase-signal-resolver.mjs --brief "{dir}/brief.md" --phase research --json
    ```
 
@@ -71,6 +73,13 @@ Supported flags:
    state machine via the CLI shim:
    `node ${CLAUDE_PLUGIN_ROOT}/lib/util/autonomy-gate.mjs --state X --event Y --gates {true|false}`.
 
+7. `--min-brief-version <ver>` — (optional) version floor for an attached
+   `--project` brief. Set **min_brief_version = {ver}** (e.g. `2.2`). Forwarded
+   to the brief-validator below as `--min-version {ver}`; an older brief emits a
+   `BRIEF_VERSION_BELOW_MINIMUM` **warning** (never blocks) because framing
+   enforcement only fires at `≥ 2.2`. Absent → no version check. See
+   `docs/HANDOVER-CONTRACTS.md` §Handover 1 for the pre-2.2 enforcement hole.
+
 Flags can be combined:
 - `--local` — local-only research
 - `--external --quick` — external-only, lightweight