chore(release): prepare 0.3.3

[iuyo5678]

Prepare the CLI, browser extension and DSH plugin for the coordinated 0.3.3 release. Align all package versions and local Cargo lock entries, finalize the October 14 changelog, and document the capabilities already merged into main: task videos, structured extraction, element waits, background tab handling and Windows signing.

Breaking DSH migration: the six browser_* tools are now named bsk_*, with no aliases for the old names. The migration guide and both main READMEs describe updating custom tool calls and policies, restarting the host and reloading /browser-skill. Publish the matching extension and CLI before the plugin.

Update both extension privacy policies for offscreen, silent task videos, MP4 downloads, local storage and access grants, 24-hour retention, authorized remote exports, deletion and the lack of automatic video-frame redaction. Update both main READMEs with video and element-wait capabilities, retention details and the migration link. Align the plugin's publishing instructions with the release-PR and staged-tag process.

Update the session focus regression to call the renamed bsk_session tool and fail explicitly if it is missing, preserving coverage for the default, --focus and --no-focus cases.

Validation completed locally:

• Version consistency, only the two local Cargo lock entries changed, previous changelog history preserved, documentation links and migration anchors checked.
• cargo metadata --offline --locked --no-deps --format-version 1 and cargo fmt --all -- --check.
• pnpm install --frozen-lockfile and full pnpm lint, including all 538 DSH tests.
• Localization tests: 64 passed; VOM tests: 82 passed; extension tests: 2,658 passed (opt-in browser/platform cases skipped).
• Opt-in video encoder browser regression passed locally using Chrome for Testing.
• node --test scripts/release.test.mjs scripts/render-version-json.test.mjs: 7 passed.
• python3 scripts/windows-release.test.py: 8 passed.
• node scripts/check-skill-bundles.mjs.
• pnpm ext:build:zip: archive manifest reports 0.3.3; every permission is described in both privacy policies.
• Extension and DSH type checks, DSH build and node scripts/check-dsh-package.mjs. Package validation used Node.js 22 / npm 10 to match CI.
• git diff --check.

After merge, use the same merge commit for the extension, CLI and plugin tags, in that order. Before extension submission, synchronize the Chrome and Edge dashboard disclosures for offscreen and video capture/export with the updated policies. Before the CLI tag, confirm the internal BK-CI signing pipeline is configured; the separate Publish CLI workflow must finish signature verification and publication before the DSH tag is pushed.