fix(functests): fix send_receipt_request 60s timeout, rebalance groups, add per-test timing

Fix send_receipt_request test that wasted 60s on every run:
- Change caps hash from sha-256 to sha-1 (profanity only supports sha-1
  for standard caps path, sha-256 goes to unsupported-hash fallback)
- Fix expected output: 'Buddy1 is online' → 'Buddy1 (laptop) is online'
  (resource is always shown for full JID presence)
- Wrap prof_output_exact in assert_true so mismatches fail fast instead
  of silently waiting the full expect_timeout

Rebalance test groups for parallel execution:
- Move Disco tests (14) from Group 3 → Group 1
- Move DB History tests (12) from Group 2 → Group 3
- Before: G1=31s G2=63s G3=30s G4=37s (bottleneck 63s)
- After:  G1=46s G2=38s G3=40s G4=36s (bottleneck 46s, -27%)

Add per-test wall-clock timing via clock_gettime(CLOCK_MONOTONIC)
in init_prof_test/close_prof_test for profiling individual tests.

tests/functionaltests/proftest.c

@@ -13,6 +13,7 @@
 #include <sys/select.h>
 #include <regex.h>
 #include <signal.h>
+#include <time.h>
 
 #include <stabber.h>
 
@@ -77,6 +78,9 @@ static size_t output_len = 0;
 /* Timeout for expect operations in seconds */
 static int expect_timeout = EXPECT_TIMEOUT_DEFAULT;
 
+/* Per-test wall-clock timer */
+static struct timespec test_start_ts;
+
 gboolean
 _create_dir(const char *name)
 {
@@ -275,6 +279,7 @@ prof_start(void)
 int
 init_prof_test(void **state)
 {
+    clock_gettime(CLOCK_MONOTONIC, &test_start_ts);
     /* Get test group from environment for static resource allocation */
     const char *group_env = getenv("PROF_TEST_GROUP");
     int group = group_env ? atoi(group_env) : 0;
@@ -427,6 +432,13 @@ close_prof_test(void **state)
     }
 
     stbbr_stop();
+
+    struct timespec now;
+    clock_gettime(CLOCK_MONOTONIC, &now);
+    double elapsed = (now.tv_sec - test_start_ts.tv_sec)
+                   + (now.tv_nsec - test_start_ts.tv_nsec) / 1e9;
+    printf("[PROF_TEST] test took %.3f s\n", elapsed);
+
     return 0;
 }