emrg: bump version to v0.2.48 (release: #839 #840 #841 #842)

[argszero]

Release v0.2.48 (rant 2026-08-18T14:46:47).

Bump: 0.2.47 → 0.2.48 across 8 files / 9 refs (standard release bump):

• emrg/__init__.py, pyproject.toml, uv.lock (emrg entry)
• emrg/gui/package.json + package-lock.json (×2)
• packaging/build-runtime.sh, make-installer.sh, make-run-installer.sh

Covers 4 commits since v0.2.47:

• emrg: TUI exit clears the terminal screen (rant 2026-08-18T11:13:17) #839 — TUI exit clears the terminal screen (rant 11:13:17)
• emrg: GUI task countdown re-fetches state on expiry (rant 2026-08-18T11:16:32) #840 — GUI task countdown re-fetches state on expiry (rant 11:16:32)
• emrg: daemon single-instance admission + truthful old-pid wait (rant 2026-08-18T12:49:09) #841 — daemon single-instance admission + truthful old-pid wait (rant 12:49:09 / 14:01:10)
• emrg: GUI tasks panel shows last-run + saturation meta (rant 2026-08-18T10:45:52) #842 — GUI tasks panel last-run + saturation meta (rant 10:45:52)

Local: pytest 938 passed + 1 skipped (939 collected), GUI 259/259, import + CLI green, test_version_sync 2/2.

[argszero]

✅ LGTM — cycle 713 (1/3). CI test + test-windows PASS (32108516434). Local: pytest 938+1 (939 collected), GUI 259/259, import + CLI green, test_version_sync 2/2. Bump diff verified — 8 files / 9 refs, 0 remaining 0.2.47 refs (uv.lock pyyaml hash is a false positive).

[argszero]

✅ LGTM — cycle 714 (2/3). Head 62846cf unchanged from cycle 713, CI test + test-windows PASS (32108516434), MERGEABLE/CLEAN. Re-verified bump: 8 files / 9 refs 0.2.47→0.2.48, test_version_sync 2/2, 0 remaining version refs.

[argszero]

✅ LGTM — cycle 715 (3rd). Head 62846cf unchanged, CI test + test-windows PASS (32108516434), MERGEABLE/CLEAN. Three consecutive LGTMs (cycles 713/714/715), no ❌ — merging. Release v0.2.48 (rant 2026-08-18T14:46:47).