v0.8.0

Feature release covering the post-0.7.0 public compatibility and agent runtime
work: P110, P111, P112, plus configurable external embedding dimensions.

Added

• Project ignore rules (P111). mempal init <DIR> and directory-mode
  mempal ingest <DIR> now respect the target project's ignore configuration
  by default: .gitignore, .git/info/exclude, global Git excludes, and
  root-level .mempalignore. Add one-off ignore files with --ignore-file;
  disable defaults with --no-gitignore or --no-mempalignore.
• Explicit MCP session peek (P112). New mempal_session_peek MCP tool reads
  a concrete Claude/Codex local session by tool + cwd, including same-tool
  cross-project reads that mempal_peek_partner correctly rejects as self-peek.

Changed

• Public issue compatibility fixes (P110). Drawer identity is source-aware
  with 12-hex ids; same-batch ingest duplicate handling is stable; Windows ~/
  config expansion works; MCP schemas stay strict-client compatible; tunnel hints
  are consistently present on-wire.
• External embedding API dimensions are configurable. Set
  embed.dimensions for non-default embedding backends; omitted values preserve
  the prior default behavior.
• README and usage docs now show crates.io install commands for the latest
  release and the correct source-checkout install path for the single-crate
  layout.