cleanup reader macros

* Fix cak7_mode guard mismatch
- cak7_mode: used by both READER_NAGRA and READER_NAGRA_MERLIN
- cak7type: used only by READER_NAGRA_MERLIN

Separate guards save 1 byte in READER_NAGRA-only builds and
ensure no unused struct members exist in any build configuration.

* cleanup reader macros

- Gate struct s_reader members, WebIF fields, and config tokens behind precise reader macros so builds exclude Videoguard/Nagra/Viaccess-only data when those modules aren’t compiled.
- Wrap AES-key helpers, reader option handlers, and Nagra/Videoguard EMM logic in the same feature flags to keep unused code out of minimal builds.
- Ensure Merlin-only arrays and filters, GPIO/ATR settings, and sendcmd handling compile only with the relevant reader backends.

thx @lpm11

Co-authored-by: default avatarWXbet <4-WXbet@users.noreply.git.streamboard.tv>

fix build without READER_NAGRA_MERLIN

The cak7type member is only defined in struct s_reader when
READER_NAGRA_MERLIN is enabled. Wrap all cak7type references
in icc_async.c and reader-nagra-common.c with the same ifdef
guard to fix compilation errors when building without
READER_NAGRA_MERLIN support.

The reader-nagra-common.c functions are shared between both
READER_NAGRA and READER_NAGRA_MERLIN. The else block (standard
NAGRA code) is always compiled and used by READER_NAGRA, while
the cak7type checks are only needed for READER_NAGRA_MERLIN.

Fixes:
  error: 'struct s_reader' has no member named 'cak7type'
  introduced in 28f2598b

reader-nagra/irdeto: change force_irdeto guard to READER_IRDETO only

force_irdeto forces a card to use the Irdeto reader instead of Nagra.
In reader-nagra.c it causes the reader to reject the card so the
Irdeto reader can handle it. This only makes sense when READER_IRDETO
is compiled - otherwise there's no Irdeto reader to take over.

Changes:
- globals.h: Change guard from (READER_NAGRA || READER_IRDETO) to
  READER_IRDETO only
- oscam-config-reader.c: Change guard to READER_IRDETO only
- module-webif.c: Change guard to READER_IRDETO only
- reader-nagra.c: Add READER_IRDETO guard around force_irdeto check

build: fix is_defined.txt generation for proper webif template filtering

The is_defined.txt file is used by pages_gen to filter templates based on enabled config options. Previously, this file was only created when explicitly calling config.sh with --enable/--disable/--restore, but not during normal builds.

The "webif clean" added in 96debcd7 ("Fix webif compression parameter") ensured pages.c was always rebuilt, but also deleted is_defined.txt which broke the filtering mechanism.

Changes:
- Call write_enabled() in make_config_mak() to ensure is_defined.txt is generated on every build
- Remove redundant "webif clean" from Makefile and CMakeLists.txt (write_enabled already deletes pages.c when needed)
- Add config.h dependency to pages.c target to trigger rebuild when config options change

This ensures proper filtering works for:
- Fresh checkouts with default config
- Builds after direct config.h modifications
- Builds after config.sh --enable/--disable changes

This feature allows limiting the number of services that can use a reader
simultaneously, essential for card readers with slot restrictions.

=== NEW CONFIGURATION OPTIONS ===

maxparallel (default: 0 = unlimited)  Maximum number of active services per reader. When reached, the reader  is skipped and other readers are tried (fallover).

paralleltimeout (default: 1000 ms)  Buffer added to the measured ECM interval for slot expiration.  A slot expires when no ECM is received within (measured_interval + timeout).

parallelfactor (default: 1.5)  Multiplier for pending slots to support zapping without blackscreen.  Set to 0 to disable pending slots (strict maxparallel enforcement).

=== ARCHITECTURE ===

Dual-slot system with active and pending services:

- Active slots (size: maxparallel)  Confirmed services actively receiving CWs from this reader.

- Pending slots (size: maxparallel * parallelfactor)  Temporary overflow during channel zapping. Pending services are  promoted to active when slots free up (FIFO), or dropped when  active services need the capacity.

Slot reservation timing:  Slots are reserved when a reader DELIVERS a CW, not when the request  is sent. This prevents readers from blocking capacity for services  they don't end up serving when multiple readers are queried in parallel.

=== BLOCKLIST FOR CLEAN FALLOVER ===

When a pending service is dropped, the client+service combination is
added to a per-reader blocklist. This causes:

- Subsequent ECM requests for blocked combinations to skip this reader
- Clean fallover to other readers without repeated drop cycles
- No log spam from services repeatedly going to pending and getting dropped

Blocklist lifecycle:
- Added: when service is dropped from pending
- Removed: when client zaps to a different service
- Cleared: when an active slot becomes free

=== TYPICAL USE CASE ===

- Reader 1: maxparallel=1 (card allows only 1 service)
- Receiver records Service A on Reader 1, user zaps to Service B
- Service B goes to pending slot (no blackscreen during zap)
- Service A sends ECM -> Service B dropped from pending
- Service B blocklisted on Reader 1 -> falls over to Reader 2
- User stops Service B -> block cleared, Reader 1 available again