chore: remove proprietary README file

- Deleted the `README.md` from the `app/proprietary` directory, which outlined licensing and usage rules for proprietary components. This removal reflects a shift in project documentation strategy and simplifies the codebase.

surfsense_backend/app/proprietary/README.md

@@ -1,44 +0,0 @@
-# `app.proprietary` — non-Apache-2 license boundary
-
-Everything in this directory tree is licensed **separately** from the rest of
-SurfSense (which is Apache-2.0), under the **Business Source License 1.1** —
-see [`LICENSE`](./LICENSE). In short: source-available; production use is
-permitted (including self-hosting the whole app) *except* offering it to third
-parties as a commercial product or hosted/managed service; each released
-version converts to Apache-2.0 four years after its release.
-
-## Why this exists
-
-This package holds the product moat:
-
-- the in-house **undetectable web crawler** (Scrapling tiers + stealth/captcha
-  hardening), and
-- (future) **platform-specific actors** that scrape/extract structured data from
-  individual platforms.
-
-Keeping it in one clearly-named directory makes the license boundary
-unambiguous: a single rule — *everything under `app/proprietary/**` is not
-Apache-2.0* — instead of per-file headers scattered across the tree.
-
-## Layout
-
-- `web_crawler/` — the Scrapling-based crawler engine. Public API:
-  `WebCrawlerConnector`, `CrawlOutcome`, `CrawlOutcomeStatus`
-  (`from app.proprietary.web_crawler import ...`).
-- `platforms/` — (future, Phase 8) platform-specific actors; scaffolded/empty.
-
-## Rules
-
-- **Do not** add Apache-2.0-intended code here.
-- Apache-2.0 code elsewhere **may import from** this package (the indexer and the
-  `web.crawl` capability do); that does not move them under this license.
-- Depend only on the public API exported from each subpackage's `__init__`, not
-  on internal modules, so the boundary stays clean and swappable.
-- **Boundary test:** put code here only if it is used *exclusively* by the moat.
-  Generic infrastructure that Apache-2 features also depend on stays Apache-2
-  even when the crawler uses it too. Example: `app/utils/proxy/` (provider
-  abstraction, registry, `CustomProxyProvider` + rotation — a thin wrapper over
-  Scrapling's public `ProxyRotator`) is shared with the YouTube/transcript and
-  chat features, so it stays Apache-2; only the crawl-ladder-coupled
-  rotation-retry orchestration (`web_crawler/connector.py::_run_tier_with_proxy_retry`)
-  lives here.