Merge origin/main into garrytan/browserharness

Resolves 52 conflicts from the merge:

VERSION + CHANGELOG + package.json: kept v1.16.0.0 (next slot above
main's v1.15.0.0). CHANGELOG entry for v1.16.0.0 (browser-skills) sits
above v1.15.0.0 (slim preamble + plan-mode E2E harness) and the rest
of main's history.

TODOS.md: kept browser-skills phases (P1 Phase 2, P2 Phase 3, P2
Phase 4) AND main's new entries (Sidebar Terminal v1.1, Structural
STOP-Ask forcing function P1).

README.md: took main's GBrain section (newer /setup-gbrain story).

browse/src/server.ts: took main's chat-queue refactor (sidebar agent
ripped in favor of interactive PTY) and re-applied browser-skills'
LOCAL_LISTEN_PORT module-level state + daemonPort plumbing through
MetaCommandOpts.

scripts/resolvers/preamble.ts: took main's reorder of AskUserQuestion
Format ahead of model overlay (v1.6.4.0 fix).

scripts/resolvers/preamble/generate-brain-sync-block.ts: took main's
slimmer version (slim preamble v1.15.0.0).

bin/gstack-brain-{init,sync}, bin/gstack-config, test/brain-sync.test.ts:
took main's mature versions (gbrain-sync shipped via #1151).

test/skill-validation.test.ts: took main's known-large-fixtures form +
removed sidebar-agent #584 assertions (file was deleted in main); kept
my Bundled browser-skills frontmatter contract block.

SKILL.md files (37 of them) + golden fixtures: took main's, then ran
`bun run gen:skill-docs --host all` to re-add the new $B skill +
domain-skill + cdp commands to the generated docs.

All 805 tests pass across browser-skills + skill-validation + gen-skill-docs.

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

package.json

@@ -9,7 +9,8 @@
     "make-pdf": "./make-pdf/dist/pdf"
   },
   "scripts": {
-    "build": "bun run gen:skill-docs --host all; bun build --compile browse/src/cli.ts --outfile browse/dist/browse && bun build --compile browse/src/find-browse.ts --outfile browse/dist/find-browse && bun build --compile design/src/cli.ts --outfile design/dist/design && bun build --compile make-pdf/src/cli.ts --outfile make-pdf/dist/pdf && bun build --compile bin/gstack-global-discover.ts --outfile bin/gstack-global-discover && bash browse/scripts/build-node-server.sh && git rev-parse HEAD > browse/dist/.version && git rev-parse HEAD > design/dist/.version && git rev-parse HEAD > make-pdf/dist/.version && chmod +x browse/dist/browse browse/dist/find-browse design/dist/design make-pdf/dist/pdf bin/gstack-global-discover && (rm -f .*.bun-build || true)",
+    "build": "bun run vendor:xterm && bun run gen:skill-docs --host all; bun build --compile browse/src/cli.ts --outfile browse/dist/browse && bun build --compile browse/src/find-browse.ts --outfile browse/dist/find-browse && bun build --compile design/src/cli.ts --outfile design/dist/design && bun build --compile make-pdf/src/cli.ts --outfile make-pdf/dist/pdf && bun build --compile bin/gstack-global-discover.ts --outfile bin/gstack-global-discover && bash browse/scripts/build-node-server.sh && git rev-parse HEAD > browse/dist/.version && git rev-parse HEAD > design/dist/.version && git rev-parse HEAD > make-pdf/dist/.version && chmod +x browse/dist/browse browse/dist/find-browse design/dist/design make-pdf/dist/pdf bin/gstack-global-discover && (rm -f .*.bun-build || true)",
+    "vendor:xterm": "mkdir -p extension/lib && cp node_modules/xterm/lib/xterm.js extension/lib/xterm.js && cp node_modules/xterm/css/xterm.css extension/lib/xterm.css && cp node_modules/xterm-addon-fit/lib/xterm-addon-fit.js extension/lib/xterm-addon-fit.js",
     "dev:make-pdf": "bun run make-pdf/src/cli.ts",
     "dev:design": "bun run design/src/cli.ts",
     "gen:skill-docs": "bun run scripts/gen-skill-docs.ts",
@@ -61,6 +62,9 @@
     "devtools"
   ],
   "devDependencies": {
-    "@anthropic-ai/sdk": "^0.78.0"
+    "@anthropic-ai/claude-agent-sdk": "0.2.117",
+    "@anthropic-ai/sdk": "^0.78.0",
+    "xterm": "5",
+    "xterm-addon-fit": "^0.8.0"
   }
 }