fix(cli): accept an MCP entry the client annotated, instead of refusing it - #1640

…ng it

OpenCode writes "enabled": true beside the "command" and "type" we write. Our
ownership check required the entry's key set to match EXACTLY
(config_json_like.c: member_count != found_count), so a three-key entry with two
recognised keys was classified as FOREIGN - and we refused to touch an entry we
had written ourselves. install then failed with:

  error: agent_config agent=OpenCode op=mcp_install path=.../opencode.json

Confirmed on two independent configs: Linux (#1630) and Windows (#1582). In
gotspatel's file EVERY MCP server carries the key - mssql, forgetful,
chrome-devtools and ours - so this is OpenCode's normal shape, not an unusual
hand-edit. Anyone who has ever toggled a server on or off in the UI was hit.

Two of my own hypotheses were wrong before the reporters' files settled it: it is
not JSONC comment parsing, and it is not the .jsonc targeting that #1575 fixed.
#1575 fixed WHICH file we open; this happens after, on what we find inside.

The distinction now reported is MATCH_WITH_EXTRAS, and the caller treats it as
ALREADY SATISFIED - success, without touching the file. That is deliberate and it
is the safe half of the fix: cbm_json_like_upsert_entry REPLACES an entry
wholesale, so writing our canonical shape over an annotated entry would silently
delete the client's keys. A refusal the user can see beats a deletion they
cannot. Doing nothing is also correct on the merits: the entry already names this
binary with the right type, which is the entire content of the install.

Merging our fields into an annotated entry while preserving the rest is the
fuller fix and stays tracked in #1630. This makes the common case work without
risking anyone's configuration tonight.

Ownership is NOT loosened otherwise: an entry whose command points at a different
binary is still foreign and still refused, byte-identically, and that direction
is pinned by its own test.

Tests use the reporters' actual entry shape. cli suite: 272 passed.

Signed-off-by: Martin Vogel <martin.vogel.tech@gmail.com>