fix(module-8): fail-fast backup check, credential walkthrough, define forge, reconcile prices

- verify-backup.sh: GIT_TERMINAL_PROMPT=0 so fetch/clone fail fast (clear warn)
  instead of hanging on an interactive credential prompt.
- README: provider-neutral first-push credential walkthrough (write scope vs 403,
  token-shown-once, invisible paste, helpers, SSH); UI labels flagged Verify.
- README: define "forge" on first prose use.
- README: reconcile the hosting price table with its own Verify caveats
  (Bitbucket/SourceHut figures web-verified; tiers/caveats no longer contradict).

Closes #38
Closes #39
Closes #47
Closes #52

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TfzV5QvtPDz8LJS3Pu5VLT

modules/08-remotes-and-hosting/lab/verify-backup.sh

@@ -15,6 +15,14 @@
 
 set -u
 
+# Fail fast instead of hanging. The clone and fetch below talk to the remote,
+# and on the HTTPS+token path with no cached credential (a common fresh-Linux
+# state) Git would stop to prompt for a username/password on the tty and block
+# this check forever. Disabling interactive prompts turns that into a clean,
+# non-zero failure that drops into the graceful warn branch below. SSH keys,
+# public repos, and cached credential helpers are unaffected.
+export GIT_TERMINAL_PROMPT=0
+
 # --- tiny output helpers (fall back to plain text if no color) ---------------
 if [ -t 1 ]; then
   GREEN=$'\033[32m'; RED=$'\033[31m'; YELLOW=$'\033[33m'; BOLD=$'\033[1m'; RESET=$'\033[0m'