Evict stale radio contacts when the contact table is full

[sg]

Problem

The radio's contact table (~350 slots) doesn't age out old contacts. Once full, the firmware just emits CONTACTS_FULL and drops the new node's advert — so new contacts never replace stale ones, and the bot logs CONTACTS_FULL indefinitely. The bot's sqlite contacts table holds 500 and acts as the long-term archive; the radio is the working set.

Solution

When enabled, the bot evicts the stalest contacts from the radio to keep radio_evict_headroom free slots:

• at startup, after device-info/contacts sync;
• automatically on CONTACTS_FULL (debounced);
• on-demand from the web UI Manage → Radio page.

Eviction operates on a fresh get_contacts(lastmod=0) dump (the DB archive may hold contacts no longer on the radio, so it can't choose victims) and never deletes DB rows — the archive is preserved. Victims are stalest-first by a fused key: bot-DB last_synced_at → radio lastmod → a plausible last_advert (garbage sender-clock timestamps are treated as oldest). Protected: configured owners, all bot users, anyone the bot DM'd in the last 24h, and any contact types in radio_evict_protect_types. Removal is capped per run and aborts after 3 consecutive radio errors; the meshcore lib's in-memory contact cache is kept in step so send_dm won't reference an evicted entry.

Config ([bot])

key	default	meaning
radio_evict_enabled	true	auto triggers (startup + CONTACTS_FULL)
radio_evict_headroom	8	keep ≥ N free slots
radio_evict_protect_types	(none)	contact types never evicted (names/ints)
radio_evict_max_per_run	50	safety cap per run
radio_evict_min_interval	120	seconds debounce for auto runs

Manual eviction works even when disabled; the switch only governs the automatic triggers. Web policy changes are runtime-only — mcbot.conf is the startup source of truth.

Web UI / API

• GET /api/radio/contacts-status, POST /api/radio/evict-contacts, POST /api/radio/contacts-policy (auth required).
• Radio tab "Contact table" card: used/max/free + protected/evictable counts, a read-only firmware autoadd-byte diagnostic, an auto-evict toggle + headroom input, and an "Evict now" button that previews victims (dry-run) before confirming. Rebuilt static assets included.

Notes

• The firmware-native set_autoadd_config is not exposed — its flag byte is undocumented (firmware source/web research were unavailable). Only a read-only autoadd_raw diagnostic is surfaced; the setter can be added later once the semantics are verified.
• "No headroom reached" is reported as a shortfall (e.g. when protections exceed capacity), never an error.

Testing

tests/test_radio_eviction.py (run with a deps-equipped Python) — victim selection ordering/protection/garbage-timestamp handling, dry-run, headroom math, per-run cap, 3-error abort, shortfall, DB-archive preservation, and the disabled-policy handler gate. All pass; existing tests/test_repeat_tracking.py still passes; web-ui builds clean.

🤖 Generated with Claude Code