2 Commits

Author SHA1 Message Date
sulthan 17ee0bd3f8 docs: correct the bot-score claims behind the browser poller (#99)
Docs only. No code changes - `git diff origin/main --stat` touches five Markdown files and adds one research note.

## What was wrong

Several docs explained Cloudflare challenges as a "bot score" that our request rate could worsen. That mechanism does not exist on these sites.

Researched live on 2026-08-12 against Cloudflare's own documentation and blog plus RFC 9309 - 22 primary pages, every claim carrying a source URL and read date, seven areas explicitly marked `Not publicly documented`. The note is `docs/research/cloudflare-bot-scoring-and-poll-cadence.md`.

- The 1-99 bot score is **Enterprise Bot Management only**. A free-plan zone has no score at all; it gets Bot Fight Mode, which matches *signatures* (headless browsers, cloud-hosting IPs).
- **No per-IP request rate is documented as an input to challenge issuance.** Volume is policed by Rate Limiting Rules, a separate opt-in product: one rule, IP-only counting, 10-second windows on Free. Published DDoS thresholds are ~1,000 errors/sec.
- **`cf_clearance` defaults to 30 minutes**, so every cadence at or above 1 hour re-solves the challenge anyway. Cadence changes how many ~4s solves happen per day and nothing else.
- The documented risk is **fingerprint quality**, which this repo already solved (real Chrome, stock UA, non-UTC clock).

## What changed

| File | Correction |
|---|---|
| `AGENTS.md` | The block is per-zone configuration plus request fingerprint, not IP reputation. comix.to turning its gate on 2026-08-12 is the worked example. Residential egress avoids the cloud-hosting-IP *signature* rather than earning a better score. The UTC measurement stands; its mechanism is now marked undocumented. |
| `backend/AGENTS.md` | Says why `_BROWSER_COOLDOWN` is longer: cost, not safety. |
| `docs/adr/0003` | Dated correction - the sites do not "bot-score" the VPS IP. Decision stands on its sweep-depth argument. |
| `docs/adr/0006` | Dated correction - no score to be better at. Decision stands on VPS memory. |
| `DEPLOY.md` | A red kagane smoke run means the Site's settings or this Chrome's fingerprint moved, not "Cloudflare's scoring". |

ADRs got dated `Corrected 2026-08-12:` paragraphs rather than silent rewrites - the record of what was decided stays intact, only the wrong mechanism is retracted.

## Deliberately not in this PR

- **The 6h browser cooldown is unchanged.** I had lowered it to 1h and reverted that; cadence is a behaviour change and belongs with the comix work in #98, not in a docs correction.
- **Two code comments still carry the myth**: `backend/main.go:83-84` ("a hammer against sites that are already bot-scoring us"). Left alone to keep this diff docs-only.

Related: #98.
Reviewed-on: #99
Co-authored-by: Sulthan Zaki <sultankiki05@gmail.com>
Co-committed-by: Sulthan Zaki <sultankiki05@gmail.com>
2026-08-12 09:32:07 +07:00
sulthan 2a3bb6922d Move the browser off the VPS to its own unit (#46) (#52)
Closes #46 once deployed.

The headless browser leaves the API stack and becomes its own compose unit
(`chrome/docker-compose.yml`) intended for the home machine, reached over the
tailnet. No fallback sidecar is left on the VPS.

The backend needs no code change — `BROWSER_WS_URL` was already the only
coupling. Its default is now empty rather than a pinned Docker IP, so an
unconfigured or unreachable browser degrades exactly as it always has: plain-TLS
libraries unaffected, kagane/novelfull logged and skipped, stored covers still
served.

### What shipped

- `chrome/docker-compose.yml` + `chrome/.env.example` — the browser unit, with
  the CDP port bound to `${BROWSER_BIND_ADDR}` (no default) and the resource
  limits from the epic: 512 MiB / 1 GiB memory+swap, `oom_score_adj 800`,
  halved CPU weight, shm 1 GiB -> 128 MiB.
- API stack drops the service, its `depends_on` and the `browser` network.
- `bookmark-api` gains the `default` network. Dropping `browser` had left it on
  `db` alone, which is `internal: true` — no published port and, worse, no
  egress for the poller at all. Caught by actually bringing the stack up.
- ADR-0006 for the topology; `DEPLOY.md` §7 for first-time setup of the browser
  machine; `REDEPLOY.md` §8 for its independent update cadence; architecture
  diagrams, config tables and troubleshooting rows across README/AGENTS/env.

### Verified locally

- Browser unit builds and runs: Chrome 151, UA carries no `HeadlessChrome`,
  all limits applied as declared.
- **Live smoke passes through the new unit**: `TestSmokeKaganeImage` fetched
  56710 bytes of `image/webp`, `TestSmokeKaganeGet` got a 200 with a real
  chapter list. The challenge cleared under the reduced 128 MiB shm.
- Bind isolation proven: refused on the host's non-loopback address, accepted
  on the configured one.
- 321 MiB peak of the 512 MiB cap after a full solve; 0 restarts, no OOM kill.
- API stack comes up clean, `/healthz` 200; egress confirmed present on
  `default` and absent on `db`.
- `go test ./...`, `go vet`, `gofmt` clean.

### Left to the operator

Provisioning the home machine, the Tailscale ACL, setting `BROWSER_WS_URL` in
production, and observing acceptance criteria 5-7 (covers with the machine off,
several days of zero OOM/restarts, VPS memory improvement). `DEPLOY.md` §7 now
carries the before/after `free -m` reading those need.

Reviewed-on: #52
Co-authored-by: Sulthan Zaki <sultankiki05@gmail.com>
Co-committed-by: Sulthan Zaki <sultankiki05@gmail.com>
2026-08-09 15:28:21 +07:00