Build dev-based branch with local memory leak and webui fixes

Summary

Create a fresh branch from upstram/dev and carry forward our local memory-leak and webui fixes that are still missing there.

Why

A strict v1.2.27 backport is not required, and clean testing shows the v1.2.27 baseline itself still has sidebar/session-list issues in local e2e. Basing on upstream dev is the lower-risk path to a working branch.

Acceptance Criteria

create a fresh local branch from upstream dev
identify local memory/webui fixes not already present upstream
cherry-pick only the missing commits
run build and focused end-to-end validation
document the final commit set and any follow-up gaps

Scoped upstram/dev branch is now in a validated good state on issue-46-scoped-picks.

Picked and integrated only the requested fixes:

long shell output handling
idle/shared MCP client cleanup and shutdown disposal
browser STT/TTS controls
Recently Active + local recent-session behavior

Follow-up integration fixes applied after cherry-picking:

resolved the remaining voice-control conflicts
restored missing Flag import in packages/opencode/src/mcp/index.ts
trimmed packages/opencode/src/cli/cmd/serve.ts back to cleanup-only behavior that fits upstram/dev
fixed local sidebar session loading for the active directory/worktree in packages/app/src/pages/layout/sidebar-workspace.tsx
wired sidebar hover prefetch through preview=true end-to-end by updating the session route contract and regenerating the JS SDK
hardened e2e project seeding in packages/app/e2e/actions.ts

Validation completed:

bun install
cd packages/opencode && bun run build
cd packages/app && bun run build
cd packages/opencode && bun test test/server/global-session-route.test.ts test/server/static-app.test.ts test/server/global-session-list.test.ts test/server/session-list.test.ts test/pty/pty-session.test.ts
cd packages/app && bun test --preload ./happydom.ts ./src/utils/runtime-adapters.test.ts
cd packages/app && bun run test:e2e:local -- e2e/prompt/prompt-voice.spec.ts e2e/sidebar/sidebar-recent-prefetch.spec.ts e2e/sidebar/sidebar-session-links.spec.ts

Current status: no known blocker on the scoped branch.

fix: finalize scoped upstream/dev picks (#46)

Remote refs updated.

origin/issue-46-scoped-picks -> c53b994b88555996e7e245be08aa1ab04190054c
origin/main -> c53b994b88555996e7e245be08aa1ab04190054c

main was force-updated with --force-with-lease after the branch passed the scoped validation and the pre-push typecheck gate.

fix: restore local install flow (#46)

Follow-up fix landed: restored the old main local-install flow on top of the scoped branch.

Restored:

root bun run install:local
package-level build:local, sign:local, copy:local, install:local, profile:memory
scripts/install-local.sh
packages/opencode/script/install-local.ts
packages/opencode/script/sign-local.ts
packages/opencode/script/memory-profile.ts

Also added the missing typed flag declaration for OPENCODE_MCP_IDLE_MS so pre-push typecheck stays green.

Validation:

cd packages/opencode && bun run typecheck
cd packages/opencode && bun run build:local
HOME=$(mktemp -d) bun run install:local from repo root, verified installed binary version from the temp home

Updated refs: