docs: add 11 missing breaking changes to MIGRATION.md

[cs-raj]

Summary

• Adds 11 new sections (8–18) to MIGRATION.md covering all breaking changes identified through a complete file-by-file code verification pass across every package in the cli and cli-plugins repos
• No existing content was modified — additions only
• Also adds MIGRATION.md to .talismanrc to suppress false-positive secret scan alerts on documentation text

What's Added

#	Section	Impact
8	Flag renames on export/import/export-to-csv	--data→--data-dir, -s, -B, --skip-app-recreation removed — scripts error immediately
9	Export directory structure changed	globalfields.json gone, schema.json gone, branches.json gone
10	V2 export + V1 import = silent data loss	Import completes "successfully" with 0 content types / 0 global fields — no warning
11	Command aliases removed	cm:export, cm:import, audit, audit:fix, tokens, cm:seed all fail
12	content-type:* deprecated flags removed	--stack, --token-alias, and 10+ short chars across 6 commands
13	--api-version removed from bulk ops	Passing it now fails; 3.2 is hardcoded
14	Short char removals across other commands	-A/-n/-B on migration, -n on app:create, etc.
15	Console log config key renamed	V1 log setting not carried over; must re-run config:set:log after upgrade
16	13 bootstrap app configs removed	8 deprecated starters + 4 sample apps gone; 8 kickstart apps remain
17	Seed stack list now curated	GitHub dynamic search gone; only 4 repos; use --repo for anything else
18	Ctrl+C exits 130 instead of exception	CI pipelines checking exit codes need updating

Test plan

• Verify all added sections render correctly in GitHub markdown
• Confirm no existing sections were modified
• Confirm .talismanrc checksum matches the current MIGRATION.md content

🤖 Generated with Claude Code

[github-actions]

🔒 Security Scan Results

ℹ️ Note: Only vulnerabilities with available fixes (upgrades or patches) are counted toward thresholds.

Check Type	Count (with fixes)	Without fixes	Threshold	Result
🔴 Critical Severity	0	0	10	✅ Passed
🟠 High Severity	1	36	25	✅ Passed
🟡 Medium Severity	0	2	500	✅ Passed
🔵 Low Severity	0	0	1000	✅ Passed

⏱️ SLA Breach Summary

✅ No SLA breaches detected. All vulnerabilities are within acceptable time thresholds.

Severity	Breaches (with fixes)	Breaches (no fixes)	SLA Threshold (with/no fixes)	Status
🔴 Critical	0	0	15 / 30 days	✅ Passed
🟠 High	0	0	30 / 120 days	✅ Passed
🟡 Medium	0	0	90 / 365 days	✅ Passed
🔵 Low	0	0	180 / 365 days	✅ Passed

ℹ️ Vulnerabilities Without Available Fixes (Informational Only)

The following vulnerabilities were detected but do not have fixes available (no upgrade or patch). These are excluded from failure thresholds:

• Critical without fixes: 0
• High without fixes: 36
• Medium without fixes: 2
• Low without fixes: 0

✅ BUILD PASSED - All security checks passed