feat(tags): add cortex-wide tag management

[Fail-Safe]

What changed

• add noema tags stats, rename, delete, and doctor with aligned text and stable JSON output
• add matching MCP tools with explicit preview/apply semantics
• support opt-in ASCII case-insensitive bulk mutation and non-interactive --yes
• preserve long-tier bodies, identity fields, content hashes, and timestamps during tag-only mutations
• make remove --force override source locking without bypassing recoverable trash
• add recover --force for source-locked recovery and reserve hard deletion for explicit purge workflows
• carry the current Homebrew authentication fix and public Rust rationale from main back onto next

Why

Noema had trace-level tag editing but no safe cortex-wide maintenance surface. Operators needed statistics, deterministic hygiene checks, and bulk changes that preview their full impact before mutation. During release qualification, remove --force was also found to contradict its recoverable-trash contract by hard-deleting immediately.

Impact

Tag maintenance is available from both the CLI and MCP. Mutating CLI commands prompt with y/N unless --dry-run or --yes is supplied; MCP mutations require an explicit apply request. Existing trace content remains unchanged by tag-only operations. remove --force is now recoverable and consistently means only “override source-lock protection.”

Validation

• make test
• make release-check
• cd plugins/obsidian && npm ci --silent && npm run build && npx tsc --noEmit
• git diff --check
• end-to-end forced trash/recovery regression in tests/remove_semantics.rs
• manual CLI validation of tag statistics, doctor plans/fixes, confirmation prompts, and deletion