feat: index Devin sessions

[BUKOWSKIREAL]

Summary

Adds Devin (Cognition's agent) as a twentieth adapter, closing #46.

Devin stores sessions in a plaintext SQLite database at ~/.local/share/devin/cli/sessions.db (XDG data dir; ~/Library/Application Support/devin is probed as a legacy macOS candidate). sessions carries metadata plus main_chain_id; message_nodes is a forest where retries and edits branch off mid-chain nodes. The visible transcript is the chain walked back from that leaf along parent_node_id. When the leaf column is missing (older schemas), dangling, or the walk cannot reach a root, the adapter falls back to every node in write order — a session body can never silently vanish.

• hidden = 1 sessions (compaction helpers, deleted sessions) and zero-content sessions are not listed.
• chat_message JSON is decoded per node: user/assistant/system/tool roles, thinking objects (sealed signatures dropped), tool_calls arguments with role="tool" rows back-filling output via tool_call_id, per-message generation_model (more authoritative than the session row's model), and metrics token counts accumulated along the main chain — including assistant nodes with empty content that still spent tokens.
• Internal traffic folds to Meta rather than counting as conversation: system rows, non-user telemetry sources (cache keep-alive), is_user_input == false, and compaction request bodies; <summary> replies collapse into CompactSummary.
• Open In resumes a session with devin --resume <id> inside its project directory (sessions are bucketed by cwd).
• Remote sync mirrors cli/sessions.db (+ WAL) under the host cache. Credentials live under ~/.config/devin, outside the data root, and are never synced.

Reviewers may want to look at crates/wake-core/src/adapters/devin.rs (schema probing, main-chain reconstruction, Meta classification) and the synthetic fixture in crates/wake-core/tests/common/mod.rs, which exercises hidden sessions, a retry side branch, keep-alive/compaction Meta folding, and token accumulation.

Closes #46

[iAmCorey]

Thanks for this! It follows Wake's adapter conventions closely, and the fixture covers the tricky parts: the retry branch, the keep-alive and compaction traffic, and token accounting. I pushed two commits to your branch:

1. Merge of main. Craft Agents (Support for Craft Agents #44) landed after you branched, and both PRs append to the same lists. Devin now comes after Craft Agents everywhere (enum and sidebar order, roster, remote layouts, brand list, chart colors, docs), the counts say twenty-one, and the CHANGELOG line credits you.
2. fix(devin):
   • When a node on the way back from main_chain_id pointed at a parent that isn't in the database, main_chain returned only the tail of the session. It now falls back to every node, which is what its doc comment already promised. It also walks indices first, so nodes are moved instead of cloned.
   • chat_message values that don't parse, and roles other than user / assistant / tool / system, are now counted as unknown lines instead of being dropped silently. Wake uses that count to notice format drift.
   • The Insights color is now the azure at the top of the icon's gradient. The previous blue was hard to tell apart from Gemini's in the stacked chart.

One question I can't answer without a Devin install. A user message is folded into Meta whenever its metadata.telemetry.source is anything other than "user". Which values of that field show up in your database? For example:

SELECT json_extract(chat_message, '$.metadata.telemetry.source') AS source, count(*)
FROM message_nodes
WHERE json_extract(chat_message, '$.role') = 'user'
GROUP BY source;

If Devin Desktop or another entry point records real prompts under a different source, those prompts would disappear from titles, search and the Insights prompt counts, and I'd add those sources to the allow-list.

I'll merge once CI is green. A fix for the source question can follow separately.

[BUKOWSKIREAL]

Data from my install (macOS, Devin Desktop — every session in sessions.db has backend_type = 'windsurf', so this covers the Desktop entry point):

SELECT json_extract(chat_message, '$.metadata.telemetry.source') AS source,
       json_extract(chat_message, '$.metadata.is_user_input')  AS is_user_input,
       count(*)
FROM message_nodes
WHERE json_extract(chat_message, '$.role') = 'user'
GROUP BY source, is_user_input;

source	is_user_input	count
user	1	3172
user	NULL	176
cache_keepalive	NULL	166

So for role = 'user' the only sources are user and cache_keepalive — real prompts, including ones typed into Devin Desktop, always record source = 'user'. Nothing else to allow-list on this install; cache_keepalive is exactly the internal traffic it's meant to fold. (Caveat: I can't speak for a pure-CLI Linux install.)

One subtlety worth knowing: the 176 source = 'user' rows with is_user_input NULL are compaction requests — their content starts with Conversation to summarize:. The source allow-list alone would not exclude them; they're only caught by the compaction-body matching already in the adapter. So that content check is load-bearing, not redundant.

Unrelated heads-up: Desktop also keeps a per-session ACP transport log at ~/Library/Application Support/devin/User/acp-messages/*.db with a different schema (messages(position, kind, payload)). The same sessions still land in sessions.db, so adapter coverage is unaffected — just flagging it in case Wake ever wants to read that store.