Add mcode-trajectory-studio: read-only session trajectory inspection via the runtime SQLite projection

A Plugin that answers questions about mcode's own sessions: which sessions exist, what
each one was for, how far it got, what the user actually asked for, what failed, and what
a background task captured. Read-only, over `~/.minimax/v2/sqlite/runtime-state.sqlite`
with the per-session `messages.jsonl` as a fallback. 13 MCP tools plus a loopback-only
web panel, zero runtime dependencies, no build step.

This commit is the plugin and everything four review rounds and a mutation sweep changed
in it. The rounds, in order, each closing reproduced defects rather than named ones:

1. Symlink escapes through task and session directories; credential redaction missing the
   forms the runtime actually stores (JSON text, escaped JSON, a key and its separator with
   a quote between); the panel's Host/Origin/Sec-Fetch-Site set described as authorization
   when it is a CSRF fence; `readOnlyHint` wrong on the one tool that starts a listener;
   and a Node floor that understated what `node:sqlite` needs.

2. Structured key names (`clientSecret`, `refreshToken`, `xApiKey`) judged by exact match,
   so they passed a value-only sweep; `stats.workspaceDir` reaching the panel unredacted
   beside the field above it that was folded; record lists bounded per string and not per
   response; a JSONL buffer that grew until EOF before the line cap was checked; and a
   documented containment boundary narrowed to match what the code enforces.

3. `/api/overview` throwing `ReferenceError` for any session with a non-empty agent
   definition — a fixture that stubbed the definition to `null` had hidden it; an event
   page trimmed to the byte budget returning the store's own cursor, so records 209–999
   of a 1000-record page were unreachable forever; and a byte ceiling implemented as a
   character count, which multibyte rows walked straight through.

4. `trajectory_tasks` advancing by rows read rather than delivered, so a byte-trimmed page
   answered "no more pages" with hundreds of tasks counted but unreachable; the JSONL
   fallback discarding `malformed` exactly when a page stopped on its look-ahead, and
   never adopting an all-corrupt artifact at all; a task-index look-ahead clamped back to
   its own cap so `capped` could never be true; `tasksOmitted` measured against the read
   window and published beside a `tasksTotal` it contradicted; and a list read that
   materialised 2,000 unbounded descriptions before egress trimming.

After those, the mutation sweep and the interfaces were audited the way a caller meets
them rather than the way they are written:

- Every record list derives its cursor from records **delivered**, counts omissions
  against the **session's own total**, and says which source it read.
- `trajectory_get` grew a `role` filter after measuring the question it opens. A 5,831-record
  session holds 11 user messages — 0.2%. Asking "what did the user say" cost one 3 MB call
  before and 19 KiB after.
- The redaction sweep is 35× cheaper on a 4 MiB response, after one rule was found
  retrying the key separator 64 times per character in text with no separator anywhere.
- `tools/mutation-sweep.mjs` runs all 34 mutation scripts serially and names its failure
  categories, because a tally nobody can reproduce is indistinguishable from a clean one.
  203 mutants, 0 survivors.
- `tools/browser-check.mjs` drives real Chrome over the DevTools protocol; it is kept out
  of the default suite because it needs a browser, and it has caught defects the unit
  tests could not see.

The panel carries a per-process 256-bit capability in the URL fragment — never sent to the
server, so never logged and never in a `Referer` — with constant-time comparison on every
`/api/*` route, and `Host`/`Origin`/`Sec-Fetch-Site` as depth. Every outbound payload is
swept once more at the boundary, so a field added later cannot leave unredacted.

CI is scoped to this Plugin: release gates, a stub-free egress contract suite driven
against the real projection, the full suite on ubuntu/macos/windows, and an engine matrix
that asserts the manifest's floor and verified range instead of describing them.

Author: weekbin

.github/workflows/mcode-trajectory-studio.yml

@@ -0,0 +1,134 @@
+name: mcode-trajectory-studio
+
+# This Plugin carries three review rounds of confidentiality, containment and
+# bounding fixes, and each round ended with the same finding from the reviewer:
+# "current tests do not cover the reproduced cases". The three fixtures that should
+# have caught them existed and were green.
+#
+# So this workflow does not re-run the repository's own `npm run check`, which
+# already covers `scripts/validate.mjs` and the whole test tree on ubuntu. It adds
+# the evidence that has been *claimed* rather than checked for this Plugin:
+#
+#   contract   The plugin-scoped gates: the release gates, then the egress contract
+#              suite that drives every tool and every route against the real
+#              projection instead of a stub store. The `/api/overview` 500 survived
+#              two rounds precisely because only stub stores exercised that path, so
+#              the stub-free suite is run as its own named step rather than folded
+#              into a count.
+#   suite      The full Plugin suite on ubuntu, macos and windows. Cross-platform
+#              evidence was previously a hand-run claim; the previous hand-run had
+#              not covered three platform assumptions in the tests themselves.
+#   engines    `tools/compat-matrix.mjs` under the documented Node floor, the lowest
+#              verified release and the current line, so the manifest's floor and
+#              verified range are asserted rather than described. On a release
+#              outside the verified range the only permitted skip is the FTS5 search
+#              test, and the tool fails if anything else is skipped.
+#
+# Scope is deliberately narrow: `paths:` filters this workflow to the Plugin plus
+# this file, so it can never block an unrelated PR. See the note in ci.yml about
+# why an unscoped "validate everything" job was removed there.
+
+on:
+  pull_request:
+    paths:
+      - 'plugins/weekbin/mcode-trajectory-studio/**'
+      - '.github/workflows/mcode-trajectory-studio.yml'
+  push:
+    branches: [main]
+    paths:
+      - 'plugins/weekbin/mcode-trajectory-studio/**'
+      - '.github/workflows/mcode-trajectory-studio.yml'
+  # Lets a maintainer, or this Plugin's author, run the same jobs outside a PR —
+  # which is how a github-hosted green check is captured on a fork whose
+  # fork-to-upstream PR cannot start Actions without maintainer approval.
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+jobs:
+  contract:
+    name: contract gates (ubuntu-latest, node 22)
+    runs-on: ubuntu-latest
+    timeout-minutes: 20
+    defaults:
+      run:
+        working-directory: plugins/weekbin/mcode-trajectory-studio
+    steps:
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          persist-credentials: false
+      - uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7.0.0
+        with:
+          node-version: 22
+      # No `npm ci`: the Plugin ships zero dependencies and no build step, which is
+      # itself part of what the release gates check.
+      - name: release gates (version, engine claims, byte units, doc anchors, egress bounds)
+        run: node tools/release-gates.mjs
+      - name: every tool and route, driven against the real projection
+        run: node --test test/egress-contract.test.mjs
+      # The browser half of this harness is manual by nature and stays out of CI.
+      # `--smoke` is the part a machine can judge, over a real loopback socket: the
+      # panel binds, the document is served hardened, the capability is required and
+      # sufficient, and the planted credential does not reach the wire. Removing the
+      # capability check makes this step fail, which is how it was verified.
+      - name: panel smoke over a real socket
+        run: node tools/panel-e2e.mjs --smoke
+
+  suite:
+    name: suite (${{ matrix.os }}, node 22)
+    runs-on: ${{ matrix.os }}
+    timeout-minutes: 25
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, macos-latest, windows-latest]
+    defaults:
+      run:
+        working-directory: plugins/weekbin/mcode-trajectory-studio
+    steps:
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          persist-credentials: false
+      - uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7.0.0
+        with:
+          node-version: 22
+      # The Plugin suite creates and removes real temporary directories and opens
+      # real SQLite projections, so it is serialised: the Windows jobs fail with
+      # EBUSY when a fixture is unlinked while SQLite still holds the file.
+      - name: plugin suite
+        shell: bash
+        run: node --test --test-concurrency=1 'test/*.test.mjs' 2>&1 | tee trajectory-suite.tap
+      - name: preserve suite output, including failures
+        if: always()
+        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
+        with:
+          name: trajectory-suite-${{ matrix.os }}
+          path: plugins/weekbin/mcode-trajectory-studio/trajectory-suite.tap
+          if-no-files-found: warn
+          retention-days: 7
+
+  engines:
+    name: engines (node ${{ matrix.node }})
+    runs-on: ubuntu-latest
+    timeout-minutes: 25
+    strategy:
+      fail-fast: false
+      matrix:
+        # 22.13.0 is the floor: node:sqlite exists, FTS5 does not. The tool requires
+        # that the FTS5 search test is the *only* skip there.
+        # 22.19.0 is the lowest release in the verified range, where FTS5 is present.
+        # 24.x is the line mcode's own engines allow today.
+        node: ['22.13.0', '22.19.0', '24']
+    defaults:
+      run:
+        working-directory: plugins/weekbin/mcode-trajectory-studio
+    steps:
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          persist-credentials: false
+      - uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7.0.0
+        with:
+          node-version: ${{ matrix.node }}
+      - name: assert the suite behaves as the manifest claims for this release
+        run: node tools/compat-matrix.mjs

plugins/weekbin/mcode-trajectory-studio/.claude-plugin/plugin.json

@@ -0,0 +1,35 @@
+{
+  "name": "mcode-trajectory-studio",
+  "version": "0.1.3",
+  "description": "只读查看本机 MiniMax Code 会话轨迹：轮次、步骤、LLM 与工具的墙钟耗时、token 用量、工具入参与结果、上下文拆分、压缩与子代理任务，并附带一个本地交互式面板。数据取自本地运行时自身的 SQLite 投影；插件不写入任何文件、不联网、不收集遥测。面板仅监听 127.0.0.1，每个 API 路由都要求一份随进程新生成的访问凭据。需要 Node.js 22.13.0+（内置 node:sqlite 的下限），已验证范围与 mcode engines 一致：>=22.19 <23 或 >=24 <27；全文检索另需内置 SQLite 带 FTS5，22.13.0-22.18.x 与 23.x 缺失时搜索降级并告警。 / Read-only inspection of local MiniMax Code session trajectories: turns, steps, LLM and tool wall-clock time, token usage, tool arguments/results, context breakdown, compactions, sub-agent tasks, plus a local panel. Data comes from the local runtime SQLite projection; the Plugin writes no files, no network, no telemetry. The panel listens on 127.0.0.1 only and requires a per-process capability token on every API route. Requires Node.js 22.13.0+ (the built-in node:sqlite floor); the verified range matches mcode engines: >=22.19 <23 or >=24 <27. Full-text search also needs FTS5 in that bundled SQLite; absent in 22.13.0-22.18.x and 23.x, where search degrades with a warning.",
+  "author": {
+    "name": "weekbin",
+    "url": "https://github.com/weekbin"
+  },
+  "homepage": "https://github.com/MiniMax-AI/MiniMax-Code-Plugins/tree/main/plugins/weekbin/mcode-trajectory-studio",
+  "repository": "https://github.com/MiniMax-AI/MiniMax-Code-Plugins.git",
+  "license": "Apache-2.0",
+  "keywords": [
+    "minimax-code",
+    "mcode",
+    "trajectory",
+    "session",
+    "telemetry",
+    "sqlite",
+    "mcp",
+    "visualization"
+  ],
+  "skills": [
+    "./skills/mcode-trajectory-studio/SKILL.md"
+  ],
+  "mcpServers": {
+    "mcode-trajectory-studio": {
+      "type": "stdio",
+      "command": "node",
+      "args": [
+        "./server/main.mjs"
+      ],
+      "cwd": "${PLUGIN_ROOT}"
+    }
+  }
+}