Simplify stats to basic counters + SMF Type 243

[mgrossmann]

Summary

Replace the 4-tier time-series statistics (~16 KB RAM, ~1,000 LOC across httpstat.c and httprepo.c) with:

1. SMF Type 243 records per HTTP request via crent370's smf_init() + smf_write() API
2. Simple in-memory counters in the HTTPD struct for operator display (/F HTTPD,STATS)

Current State (to be removed)

File	LOC	Description
httpstat.c	509	4-tier time-series (month/day/hour/min), HTTPSTAT records, dataset load/save
httprepo.c	419	Apache Combined Log Format formatter + httpstat_add()

HTTPD struct fields to remove: st_month, st_day, st_hour, st_min, st_dataset, cfg_st_*_max, FILE *stats

New Design

SMF Type 243 Record (httpsmf.c, ~50 LOC)

#define SMF_TYPE_HTTPD     243
#define SMF_HTTPD_REQUEST  1

struct smf_httpd_request {
    SMF_HEADER      hdr;            /* 18 Bytes Standard SMF Header */
    char            ssi[4];         /* "HTTP"                       */
    short           subtype;        /* 1 = Request completed        */
    char            userid[8];      /* RACF User (blank if none)    */
    unsigned int    client_addr;    /* Client IPv4                  */
    short           resp_code;      /* HTTP Status Code             */
    unsigned int    bytes_sent;     /* Response Bytes               */
    unsigned int    duration_us;    /* Request duration microseconds*/
    char            method[8];      /* GET/POST/PUT/DELETE          */
    char            uri[64];        /* Request URI (truncated)      */
};

In-Memory Counters

unsigned    total_requests;
unsigned    total_errors;
unsigned    total_bytes_sent;
unsigned    active_connections;

/F HTTPD,STATS displays these via WTO — no dataset I/O.

Implementation Steps

1. Delete httpstat.c — remove HTTPSTAT arrays/fields from HTTPD struct, remove httpstat_load()/httpstat_save() calls, replace httpstat_report() with counter display, remove stats parmlib keywords
2. Delete httprepo.c, create httpsmf.c — SMF record + counter increment + state transition
3. Add counters to HTTPD struct — replace old st_* fields

No access log in 4.0.0 — can be added as optional feature later.

Dependencies

• crent370 SMF API (smf_init() + smf_write()) must be implemented first
• SMF must be activated in SYS1.PARMLIB(SMFPRMxx): SYS(TYPE(243))

Acceptance Criteria

• httpstat.c deleted
• httprepo.c deleted, replaced by httpsmf.c
• No HTTPSTAT arrays in HTTPD struct (~16KB RAM freed)
• No dataset load/save at start/shutdown
• No access log (FILE *stats removed)
• SMF Type 243 records visible in SYS1.MANX after HTTP requests
• /F HTTPD,STATS shows simple counters (requests, errors, bytes, connections)
• Existing functionality (curl, Zowe, mvsMF) not affected