docs: comprehensive documentation audit and update

[BigMichi1]

• Update command count from 12 to 15 across all docs
• Add /notifications, /stats, /logs, /deleteaccount to all references
• Document AES-256-GCM credential encryption (crypto.ts)
• Add loot_totals table to database schema documentation
• Fix type definition path from src/lib/ to src/bot/api/types/
• Expand test inventory from 3 to 11 files (110+ tests)
• Fix DB table names (redeemed_codes, backfill_operations)
• Update Bun version from 1.0 to 1.3.14 in docs/mise.md
• Add detailed command sections for new commands in full-documentation.md
• Update CHANGELOG [Unreleased] with all new features
• Update security-assessment with AES-256-GCM and /deleteaccount mitigations
• Update .instructions.md and SECURITY.md slash command counts

[github-actions]

✅ Coverage Report

Metric	Value
Current coverage	71.49% (1620/2266)
Baseline coverage	71.49% (1620/2266)
Result	PASS

[Copilot]

Pull request overview

Documentation-only PR to align the project’s published docs (README + detailed docs + security docs) with the current bot feature set, including new slash commands, credential encryption, expanded tests, and updated database schema references.

Changes:

• Updates docs to reflect 15 slash commands, adding /notifications, /stats, /logs, and ensuring references are consistent across documentation.
• Documents AES-256-GCM credential encryption (via ENCRYPTION_KEY) and the loot_totals aggregate table used for stats.
• Updates test inventory counts/coverage notes and refreshes tooling docs (e.g., Bun 1.3.14).

Reviewed changes

Copilot reviewed 12 out of 12 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
SECURITY.md	Updates command counts referenced by security/process documentation.
README.md	Updates feature list and command list to include new commands and encryption.
docs/testing-strategy.md	Expands the documented test inventory and updates pass criteria wording.
docs/system-design.md	Updates actors/actions and database table descriptions (including loot totals + encryption).
docs/structure.md	Updates repo structure notes (command count, utils contents, type path).
docs/security-assessment.md	Updates mitigations/recommendations to include AES-256-GCM and /deleteaccount.
docs/mise.md	Updates Bun version pinning guidance in Mise documentation.
docs/full-documentation.md	Adds detailed sections for new commands and updates architecture/schema notes.
docs/development.md	Updates development guide structure, test list, and schema/ERD documentation.
docs/api-reference.md	Updates command count and adds new command reference sections + updated code-detection regex docs.
CHANGELOG.md	Updates Unreleased notes to include new features/commands/encryption/loot totals.
.instructions.md	Updates references to command counts and API reference scope.

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