Replace Printf.printf with print_endline for simple string output.

- Add err_invalid_cidr helper (E340)
- Rename get_client_ip→client_ip, client_ip→first_xff_ip, get_client_ip_string→client_ip_string (E325/E331)
- Rename test_get_ip_no_crash in fuzz (E320)
- Replace Printf.sprintf with Fmt.str in fuzz (E205)
- Add module doc and suite doc to fuzz_xff.mli (E400/E405)
- Fix private_ranges doc format (E410)
- Create fuzz.ml runner; update dune to use (name fuzz) (E718)
- Extract suite from test_xff.ml; add test.ml runner and test_xff.mli (E600)

- Change `run` signature to `string -> (string * test_case list) list -> unit`
matching Alcotest's grouping convention
- Fix `_name` bug: pass the name through to Alcotest.run_with_args
- Each fuzz module now exports `let suite = ("name", [test_case ...])`
- Entry points (fuzz.ml) collect suites: `Crowbar.run "pkg" [Fuzz_X.suite]`
- Remove stale `add_test`/`suite` API, keep only `test_case`/`run`
- Remove `let run () = ()` from fuzz_common.ml files
- Update merlint E725 rule to match new `let suite = ("name", ...)` pattern
- Update E725 test fixtures and expected output

- Restore cursor on exit via at_exit in Tty.Progress (fixes TTY corruption)
- Install SIGINT handler in monopam test for clean Ctrl-C
- Add 2s per-iteration timeout and 2s total budget to crowbar
- Group crowbar alcotest output by module prefix ("mdns: foo" → group "mdns")
- Skip fuzz runtest in afl context (enabled_if <> profile afl)
- Add merlint E725: enforce "module: description" fuzz test name convention

Convert all packages from:
(source (uri https://tangled.org/handle/repo))
to:
(source (tangled handle/repo))

This uses dune 3.21's native tangled support for cleaner source
declarations. Also removes redundant homepage/bug_reports fields
that are auto-generated from tangled sources.

Comprehensive seed corpus for efficient AFL fuzzing:

Text/Protocol formats:
- cookeio: HTTP cookies (simple, full attributes, multi-value)
- jsonwt: JWT tokens (header, valid token)
- json-logs: JSON strings with escapes
- tomlt: TOML config files
- hostname: Domain names with ports
- xff: X-Forwarded-For headers, CIDR notation
- punycode: ASCII and Unicode domains
- mdns: DNS headers and queries

Binary formats:
- sdnv: RFC 6256 variable-length integers
- hap: HomeKit TLV encoding
- space-packet: CCSDS packet headers
- tc-1/tm-1: Telecommand/Telemetry frames
- sle: Space Link Extension TML headers
- tls: TLS records and handshake messages
- requests: HTTP/1.1 and HTTP/2 frames

Crypto:
- crypto: 32-byte keys
- csrf: CSRF tokens and secrets
- paseto: v3.local prefix and keys
- pbkdf2: passwords and salts
- spake2/srp: authentication parameters
- streaming-aead: keys, nonces, plaintext

Misc:
- sgp4: TLE satellite orbit data
- tty: ASCII, Unicode, ANSI escape sequences
- github-oauth: OAuth parameters
- rate-limit: IPv4/IPv6 addresses

Update comment headers to use standardized format:
- Quick check: dune build @fuzz
- With AFL: crow start --cpus=4

Remove verbose afl-fuzz commands and fuzz-afl aliases since
crow now handles building and running AFL instrumented fuzzers.