fix: auto-update prebuilt binaries for all platforms

[SiliconState]

Summary

• trigger prebuilt builds on pushes/PRs that modify native code or the build workflow
• commit refreshed prebuilt binaries back to the repo from CI on pushes to main
• update prebuilds documentation to reflect committed platform coverage

Type of change

• Bug fix
• Feature
• Docs
• Refactor

Validation

• npm run setup
• npm run doctor
• npm run test:smoke
• Workflow logic reviewed for Linux/macOS/Windows prebuild generation

Checklist

• Scoped change (no unrelated edits)
• Docs updated for behavior changes
• Keeps C + SQLite core lightweight

Before

Linux and Windows prebuilds were CI/release targets but were not committed to the repository, so users without a local C compiler had to build from source.

After

When native code changes on main, CI rebuilds platform prebuilts and commits them back to prebuilds/, making those binaries available to installs without requiring a compiler.

[SiliconState]

Validation note:\n\n- Verified locally on Linux x64 with no compiler in PATH\n- Copying prebuilt binary for linux-x64 -> /home/abaka/.pi/memory/pi-memory
Installed: /home/abaka/.pi/memory/pi-memory
Done. copied pi-memory v2.2.0 — durable agent memory store
db: ~/.pi/memory/memory.db
project: auto-detected from PI_MEMORY_PROJECT | git remote | cwd | 'global'

Commands:
init [] [--file ] bootstrap MEMORY.md for any project
projects list all projects with record counts

log decision <title>       --choice <str>
                           [--context <str>] [--rationale <str>]
                           [--alternatives <str>] [--consequences <str>]
                           [--tags <str>] [--project <proj>]
                           [--session-id <id>]

log finding  <content>     [--source <str>] [--category <str>]
                           [--confidence verified|assumption|unverified]
                           [--tags <str>] [--project <proj>]
                           [--session-id <id>]

log lesson   <what_failed> [--why <str>] [--fix <str>]
                           [--tags <str>] [--project <proj>]
                           [--session-id <id>]

log entity   <name>        [--type <str>] [--description <str>]
                           [--notes <str>] [--project <proj>]
                           [--session-id <id>]

query   [--project <proj>] [--type decision|finding|lesson|entity] [--limit <n>]
search  <keyword>          [--project <proj>] [--limit <n>]
recent  [--n <n>]
state   <project>          [--phase <str>] [--summary <str>] [--next <str>]
export  [--project <proj>] [--format md|json]
sync    <file>             [--project <proj>] [--limit <n>]

ingest-session <path.jsonl>   [--project <proj>] [--dry-run]
sessions                      [--project <proj>] [--limit <n>]

Defaults: --project --limit 20 --n 10 --confidence assumption
--session-id links a memory entry to a specific Pi session UUID
--next takes pipe-separated values: "task1|task2|task3"
sync replaces and
markers in
ingest-session parses a Pi .jsonl session file, stores session metadata
and compaction summaries as findings. Idempotent (re-ingest updates).
set PI_MEMORY_PROJECT= to pin project in any shell or script instead of compiling\n- Verified the installed binary runs: \n- Simulated package install via

@siliconstate/pi-memory@2.2.0 postinstall
node ./scripts/postinstall.mjs

[pi-memory] native binary installed in the user .pi/memory directory.

up to date, audited 1 package in 181ms

found 0 vulnerabilities in a fresh temp copy; succeeded and installed the binary without requiring a compiler\n\nThis means a fresh install can succeed from committed prebuilts on Linux, while CI now verifies/prepares prebuilts for macOS, Linux, and Windows.

[SiliconState]

Validation note:

• Verified locally on Linux x64 with no compiler in PATH
• node ./scripts/setup.mjs copied prebuilds/linux-x64/pi-memory instead of compiling
• Verified the installed binary runs: pi-memory v2.2.0
• Simulated package install via npm install in a fresh temp copy; postinstall succeeded and installed the binary without requiring a compiler

This means a fresh install can succeed from committed prebuilts on Linux, while CI now verifies/prepares prebuilts for macOS, Linux, and Windows.