v7.55.1

Fixed

• The bd close review gate, the subagent-stop block and MCP auto-approve were all inert in 7.55.0. A Claude Code hooks.json entry of "type": "mcp_tool" cannot return a verdict — the harness names four hook types that carry a decision (prompt, agent, command, http) and mcp_tool is not among them. RDR-215 rewired 21 entries across the two tiers and swept these three onto the tool tier with everything else, so each returned a correct verdict that was discarded. They now run as nx-hook verbs on the command tier: a console script in the wheel, exec form, no shell and no plugin script, so the fix does not walk back RDR-215's direction. nexus.mcp.hooks.DECIDING_HOOKS names the set and a test refuses a hooks.json that puts any of them back. (nexus-17i1n)

• The close gate was silently disabled in every git worktree. .nexus.yml is gitignored by design, so there is one per repo and it lives in the primary checkout; the reader resolved it from the process cwd and every linked worktree got the defaults, both gates off. It now resolves from the git common dir — identical for anyone not using worktrees. The on_close: false branch also said nothing at all; it now states that an allow is by configuration rather than by verification, because a gate that declines to gate without a word is indistinguishable from one that checked and was satisfied. (nexus-634ye)

• Three more hooks were dead because an MCP server gets no usable CLAUDE_PLUGIN_ROOT. conexus/.mcp.json set it to the literal ${CLAUDE_PLUGIN_ROOT} — Claude Code does not expand ${...} in an MCP env block — and a non-empty literal is truthy, so callers built a path that can never exist while the documented unset fallback never ran. Consequences: session-end verification read an empty config and verified nothing; every dispatched subagent received context with its whole T2 Memory section missing; and the RDR-205 ledger projection wrote nothing at all, on every SubagentStart and SubagentStop, since v7.41.0. Fixed by porting the three scripts into the wheel (nexus.hooks.verification_config, nexus.hooks.t2_prefix_scan, nexus.hooks.tuple_ledger_project) so nothing needs the plugin root, rather than by teaching the hooks to find it. (nexus-b5ugt)

• The env blocks are removed from both server entries in conexus/.mcp.json. There is no correct value to put there, and a new lint walks both plugins' .mcp.json refusing any env value that is an unexpanded placeholder. (nexus-2xso4)

• _bd_verbs did not see a bd close inside a brace group or a subshell, so { bd close nexus-x; } closed without a review marker on either payload path. (nexus-17i1n)

Changed

• nx-hook gains three verbs: pre-close-verification, subagent-stop, auto-approve. All three remain registered as MCP tools as well — the verdict is useful as data — but hooks.json wires the command tier.
• DataTokenManager.fresh_lease_token(): a read-only peek at an existing data-token lease that never mints and never touches the in-process cache.

Engine

• Pinned engine identity unchanged: engine-service-v0.1.129.