Restore a single source of truth for project status and conventions, and
fix the broken doc links left by prior "remove old documentations" cleanups.

- Restore document/status/current.md as the single progress truth source
  (qualitative status, no percentages); converge README/CLAUDE.md/todo to it
- Add /status slash command (first cognitive/orientation command)
- Make AGENT.md the single convention source; CLAUDE.md (@AGENT.md) and
  AGENTS.md become thin Claude/Codex entry points referencing it
- Share the AI hub via git (was gitignored): track .claude/commands/,
  settings.json, CLAUDE.md, AGENTS.md; keep MEMORY.md/BLUEPRINT.md/
  settings.local.json private
- Fix ~25 broken doc links (deleted done/*_status.md, missing milestone_01,
  MaterialRules.md, quick_start path)
- Dispatch upper layers (current.md, AGENT.md) to HandBook/scripts as the
  detail truth source

- Point git core.hooksPath at scripts/release/hooks/ (version-controlled);
  cmake/install_hooks.cmake sets it at configure time so hooks work right
  after clone — no manual install_hooks.sh needed
- Rename pre-commit.sample/pre-push.sample -> pre-commit/pre-push; CRLF -> LF
- Add three-layer dependency check to pre-commit (blocks base->ui/desktop,
  ui->desktop) — rules were documented in AGENT.md but not enforced on commit
- Make PROJECT_ROOT position-independent (git rev-parse --show-toplevel);
  required after moving hooks from .git/hooks (2 levels deep) to
  scripts/release/hooks (3 levels) — without it every check silently ran in
  the wrong cwd and no-op'd
- Add .clang-tidy naming config (config-only; not enforced in pre-commit/CI)
- Document the full discipline in AGENT.md "Code Quality Discipline"

- install_hooks.ps1: reference pre-commit/pre-push directly (was *.sample,
  which no longer exists after the core.hooksPath rename); add core.hooksPath
  recommendation in header
- install_hooks.sh: rename local sample_name -> source_name (hooks are no
  longer .sample files)

- .clang-tidy: fix naming to match the actual codebase — private members
  use the m_ prefix (was wrongly configured as _ suffix); constants are
  plain UPPER_CASE (drop the invented k prefix)
- AGENT.md: document the deliberate Doxygen two-tier model — lint.py is
  the enforced floor (codebase passes), DOXYGEN_REQUEST.md is the
  aspirational target (class @code, @author/@Date) that does not block
  commits

Distill the codebase's actual style preferences (data-backed) so new code and
AI tools match the project: prefer cf::expected for errors (reduce exceptions),
unique_ptr + make_unique ownership (shared_ptr only for shared ownership),
heavy auto/constexpr/string_view, interface-driven design with strict override,
and Qt without Q_DISABLE_COPY. These are preferences, not lint-enforced.

Resolve develop/main divergence for PR #6. Keep document/status/current.md as the status single source of truth (develop's doc architecture); main's #5 deleted it but left a dangling reference in document/todo/index.md. Adopt develop's todo/index.md (drops links to deleted done/*_status.md files and deprecated percentage notation).