chore: bump version and changelog (v1.51.0.0)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

CHANGELOG.md

@@ -1,5 +1,58 @@
 # Changelog
 
+## [1.51.0.0] - 2026-05-27
+
+## **Long-running browser sessions hold flat RSS on the Bun side. `$B memory` gives every future OOM receipts instead of a screenshot.** Four CDP-resource leak classes closed and pinned with tripwires; a structured diagnostic surfaces Bun heap + per-tab JS heap + Chromium process tree + bounded buffer sizes in real time.
+
+This release closes four leak classes in the browse server that compounded silently across long sidebar sessions: response-body materialization in the requestfinished listener (multi-GB/hour Buffer churn on media-heavy pages), three undetached CDP session call sites (cdp-bridge, write-commands archive, cdp-inspector), an unbounded modificationHistory array in the CSS inspector, and SSE subscriber cleanup that only fired on the abort edge — TCP-died-without-abort cases (Chromium MV3 service-worker suspend, intermediate proxy half-close) left subscribers in the Set forever holding the controller and any queued bytes. All four have invariant tests; a static-grep tripwire fails CI if a future refactor reintroduces direct `newCDPSession(...)` calls outside the helper module.
+
+Alongside the fixes, `$B memory` and `/memory` ship the diagnostic the original 160 GB OOM investigation was missing: Bun RSS + heap breakdown, per-tab JS heap via CDP `Performance.getMetrics`, Chromium process tree via `SystemInfo.getProcessInfo` (PID + type + CPU), and the bounded buffer sizes (modificationHistory, activity subscribers, inspector subscribers, console/network/dialog buffers, capture buffer bytes). The sidebar footer polls `/memory` every 30s with adaptive backoff (drops to 5min if response time exceeds 2s), and a tab-count guardrail fires soft-warn at 50 / hard-warn at 200 with a top-5-by-RAM toast offering one-click close. Single-tab JS heap above 4 GB triggers an immediate toast, catching the WebGL/video runaway case where one tab balloons without the count ever reaching 200.
+
+### The numbers that matter
+
+Source: this branch's 16 commits + the post-merge audit reports. Net diff: 23 files changed, +2251 / -143 = 2394 LOC across browse server (TypeScript), gstack extension (JS/HTML/CSS), and tests.
+
+| Capability | Before this PR | After this PR |
+|---|---|---|
+| `requestfinished` body handling | `await res.body()` on every response, allocates full body Buffer for one `.length` read | `req.sizes()` reads structured byte count from `Network.loadingFinished`, zero body materialization, accurate for chunked / gzip / streaming responses |
+| CDP session lifecycle (3 sites) | direct `newCDPSession`, detach missing or success-path-only | `withCdpSession` (try/finally detach) + `getOrCreateCdpSession` (cached + close-detach) helpers, all 3 sites migrated, static-grep tripwire prevents regression |
+| modificationHistory in CSS inspector | unbounded array, grew for every `$B css` edit across the session | bounded FIFO cap 200, evicted-count surfaced in the undo error so the user knows why their target index is gone |
+| SSE subscriber cleanup | abort-edge only; TCP-died-without-abort leaked subscriber + controller + queued bytes until process exit | `createSseEndpoint` helper with cleanup on abort + enqueue-throw + heartbeat-throw, idempotent (any edge fires once) |
+| Tab-count visibility | none — user could accumulate hundreds of tabs without warning | soft warn at 50 (activity entry), action toast at 200 (top 5 by RAM + Close-selected + Snooze), single-tab >4 GB triggers immediate toast |
+| Diagnostic command | not available | `$B memory` (text + `--json`), `/memory` endpoint (SSE-session-cookie gated), sidebar footer with adaptive backoff |
+| Net change in `server.ts` (SSE refactor) | 132 lines of inline ReadableStream wiring across two endpoints | 23 lines, both endpoints route through one helper |
+| Test pins for the leak class | none specific | 6 new test files, 45 new tests; static-grep tripwire fails CI on regression |
+
+### What this means for builders
+
+The next time you leave a gbrowser session running for days, the Bun side holds its RSS flat instead of churning on per-response Buffer allocations. If a tab does go rogue, the sidebar footer shows you in real time — `RSS: 5.6 GB · 12 tabs`, color-coded — and a 200-tab toast surfaces the top RAM consumers with one-click close before you hit the OS OOM killer. If the next OOM still fires, `$B memory` is there to give it receipts instead of theory: Activity Monitor says 160 GB; the diagnostic tells you which process tree, which tabs, and which in-memory structures are holding it. Every code path the diagnostic measures is also bounded — modificationHistory at 200, console/network/dialog buffers at 50K via the existing CircularBuffer, SSE subscribers via the new cleanup contract — so the bookkeeping itself can't leak.
+
+### Itemized changes
+
+#### Added
+- **`$B memory` command** in `browse/src/memory-command.ts` — text mode with sorted top-10 tabs + "and N more" tail; `--json` mode for programmatic consumers and the sidebar footer poll.
+- **`/memory` HTTP endpoint** in `browse/src/server.ts` — same SSE-session-cookie auth model as `/activity/stream`. Deliberately NOT extending `/health` (which already leaks AUTH_TOKEN in headed mode per TODOS.md "Audit /health token distribution").
+- **`BrowserManager.getMemorySnapshot()`** — collects Bun process memory + per-tab JS heap via `Performance.getMetrics` (lazy per tracked page, swallows target-died errors) + Chromium process tree via `Browser.newBrowserCDPSession()` + `SystemInfo.getProcessInfo`.
+- **`browse/src/memory-snapshot.ts`** — shared types (`MemorySnapshot`, `MemoryTabSnapshot`, `MemoryProcess`, `MemoryStructureStats`) plus `formatBytes()` renderer (4 tiers, 2 decimals at GB).
+- **`withCdpSession(page, fn)`** and **`getOrCreateCdpSession(page, cache)`** in `browse/src/cdp-bridge.ts` — lifecycle helpers for one-shot and cached CDP work. Every direct `newCDPSession` call site now routes through one of them.
+- **`createSseEndpoint(req, config)`** in `browse/src/sse-helpers.ts` — owns the SSE cleanup contract (abort + enqueue-throw + heartbeat-throw, all idempotent). Built-in lone-surrogate sanitization on every JSON.stringify.
+- **Sidebar footer RSS readout** in `extension/sidepanel.{html,js,css}` — polls `/memory` every 30s with 5-minute backoff if response time exceeds 2s. Color-coded thresholds: orange at 2 GB Bun RSS or 50 tabs, red at 8 GB or 200 tabs.
+- **Tab guardrail UX** in `extension/sidepanel.js` — top-5-by-RAM toast at 200 tabs OR any single tab over 4 GB JS heap, with checkboxes + Close-selected (via `$B closetab`) + Snooze persisted in `chrome.storage.session`. Snooze bumps the thresholds so the toast stays hidden until the user accumulates more tabs or one tab grows another 2 GB.
+- **Static-grep tripwire** (`browse/test/cdp-session-cleanup.test.ts`) — fails CI if any source file outside `cdp-bridge.ts` calls `newCDPSession(...)` directly.
+- **45 new tests across 6 files** pinning the leak-fix invariants: CDP session lifecycle (8), SSE cleanup contract (6), modificationHistory cap + evicted-aware error (7), tab guardrail fires-once + re-arms (6), body-materialization reproducer (1), `$B memory` formatter + byte renderer + JSON entry (17).
+- **4 follow-up entries in `TODOS.md`** (P2: MV3 SW memory profile, P2: native + GPU memory breakdown, P3: single-context CDP listener via `Target.setAutoAttach`, P3: real-Chromium peak-RSS reproducer for periodic tier).
+
+#### Changed
+- **`wirePageEvents.requestfinished` no longer materializes response bodies.** Pre-fix: `await res.body()` allocated a Bun `Buffer` of the full response on every fetch just to read `.length`. Post-fix: `req.sizes()` pulls the structured byte count from `Network.loadingFinished` without body fetch. Accurate for chunked transfer, gzip-encoded responses, and streaming media.
+- **`modificationHistory` capped at 200 entries with FIFO eviction.** `undoModification` error now reports `"No modification at index N. History has 200 entries (most recent 200 only — M earlier entries evicted at the cap)."` when the requested index is out of range AND the buffer has overflowed.
+- **`/activity/stream` and `/inspector/events` refactored through `createSseEndpoint`.** Both endpoints collapse from ~45 lines of inline `ReadableStream` wiring to ~8 lines of helper config; behavior preserved bit-for-bit.
+- **`memory` command classified under the `Server` category** in `COMMAND_DESCRIPTIONS` so it appears in the generated SKILL.md tables alongside `status` / `restart` / `handoff`.
+
+#### For contributors
+- Plan completion audit: 12 of 17 plan items DONE, 2 CHANGED (deliberate scope decisions documented in the relevant commits — `req.sizes()` swap simpler than a single-context CDP listener; tab guardrail action toast wired through `$B closetab` instead of a `chrome.tabs.remove` bridge), 1 deferred to periodic tier (UI E2E tests).
+- Coverage audit: 44% pre-diagnostic-tests → ~62% after adding the formatter coverage. Strong paths (CDP session lifecycle, body materialization, history cap, tab guardrail, SSE cleanup) all at 100% with invariant tests. Extension UI tests deferred (no extension test harness in this repo today).
+- The CDP-session cleanup tripwire is the most reusable artifact here — any future addition of CDP work should route through the two helpers. Trying to call `newCDPSession` outside `cdp-bridge.ts` fails CI immediately with a pointer to the right helper.
+
 ## [1.48.0.0] - 2026-05-26
 
 ## **Agents stop dropping AskUserQuestion options when there are 5+.** A new canonical preamble rule + runtime gate makes Conductor's 4-option cap a split-or-batch decision, not a silent trim.

VERSION

@@ -1 +1 @@
-1.48.0.0
+1.51.0.0

package.json

@@ -1,6 +1,6 @@
 {
   "name": "gstack",
-  "version": "1.48.0.0",
+  "version": "1.51.0.0",
   "description": "Garry's Stack — Claude Code skills + fast headless browser. One repo, one install, entire AI engineering workflow.",
   "license": "MIT",
   "type": "module",